221221101211212 has 24 divisors (see below), whose sum is σ = 524644578830512. Its totient is φ = 72531508593600.

The previous prime is 221221101211211. The next prime is 221221101211247. The reversal of 221221101211212 is 212112101122122.

It is a super-2 number, since 2×221221101211212² (a number of 29 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (221221101211211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 151107308839 + ... + 151107310302.

Almost surely, 2^{221221101211212} is an apocalyptic number.

It is an amenable number.

221221101211212 is an abundant number, since it is smaller than the sum of its proper divisors (303423477619300).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221221101211212 is a wasteful number, since it uses less digits than its factorization.

221221101211212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 302214619209 (or 302214619207 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 21.

Adding to 221221101211212 its reverse (212112101122122), we get a palindrome (433333202333334).

The spelling of 221221101211212 in words is "two hundred twenty-one trillion, two hundred twenty-one billion, one hundred one million, two hundred eleven thousand, two hundred twelve".