title: why rsa public key is number but public key is alphabet?
body: <p>When I check a <code>.crt</code> file, I see:</p>
  <pre><code>$ openssl x509 -in server.crt -text
  
  //bla bla bla
          Subject Public Key Info:
              Public Key Algorithm: rsaEncryption
                  RSA Public-Key: (2048 bit)
                  Modulus:
                      00:9a:b4:f0:e7:15:58:9d:3c:1a:46:45:24:2d:e8:
                      3a:2a:4b:5c:1a:2d:7f:9a:0b:28:e5:d3:cb:0d:c7:
                      a4:a4:fd:4b:4e:94:c7:dd:f0:8f:14:e5:78:c7:27:
                      a7:9a:c9:4e:6f:a9:fb:9a:68:fe:54:7e:d0:a3:69:
                      de:00:2d:7c:5d:93:87:e6:17:2a:bd:93:bb:2c:34:
                      b1:cf:23:a5:44:d2:ab:2a:e3:72:71:24:a7:cb:32:
                      b3:f7:9d:85:66:4b:d6:72:2a:e3:25:fc:c8:06:8a:
                      a1:ea:a5:65:e8:75:7d:89:3e:cd:90:24:4c:48:da:
                      a4:f5:ea:ba:b4:af:ee:55:18:b4:95:8b:00:74:98:
                      a0:00:45:57:83:4e:f5:23:9f:e1:f0:5b:47:5f:a7:
                      99:40:55:75:10:fd:c9:b3:b1:5e:17:43:b4:86:b1:
                      0f:95:5f:b0:50:45:f2:6d:7c:63:96:1d:ba:2c:97:
                      73:87:4d:54:fb:8a:72:5e:da:ea:e1:37:33:aa:ce:
                      a2:3f:07:f8:f7:96:3e:f0:c7:5e:c4:10:c7:40:0a:
                      8a:52:1b:27:0e:46:d5:7e:04:49:f4:1d:25:0a:af:
                      6a:4d:46:3c:ff:06:40:84:4e:f6:c6:af:8b:b0:0d:
                      c7:48:68:1f:ed:c9:df:13:e7:ad:7e:55:35:06:ad:
                      3a:05
  </code></pre>
  <p>which shows an RSA public-key is numbered, but, when I check the same file for public-key, it shows an alphabet key:</p>
  <pre><code>$ openssl x509 -in server.crt -pubkey -noout
  
  -----BEGIN PUBLIC KEY-----
  MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAmrTw5xVYnTwaRkUkLeg6
  KktcGi1/mgso5dPLDcekpP1LTpTH3fCPFOV4xyenmslOb6n7mmj+VH7Qo2neAC18
  XZOH5hcqvZO7LDSxzyOlRNKrKuNycSSnyzKz952FZkvWcirjJfzIBoqh6qVl6HV9
  iT7NkCRMSNqk9eq6tK/uVRi0lYsAdJigAEVXg071I5/h8FtHX6eZQFV1EP3Js7Fe
  F0O0hrEPlV+wUEXybXxjlh26LJdzh01U+4pyXtrq4Tczqs6iPwf495Y+8MdexBDH
  QAqKUhsnDkbVfgRJ9B0lCq9qTUY8/wZAhE72xq+LsA3HSGgf7cnfE+etflU1Bq06
  BQIDAQAB
  -----END PUBLIC KEY-----
  </code></pre>
  <p>Why is one of them a hexadecimal number while the other same key is an alphabet?</p>
  <p>(Note: I've created a self-signed key, if it helps.)</p>