21221112001212 has 60 divisors (see below), whose sum is σ = 56014782359536. Its totient is φ = 7005027251520.

The previous prime is 21221112001097. The next prime is 21221112001253. The reversal of 21221112001212 is 21210021112212.

21221112001212 is a `hidden beast` number, since 21 + 221 + 11 + 200 + 1 + 212 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 317914489 + ... + 317981232.

Almost surely, 2^{21221112001212} is an apocalyptic number.

It is an amenable number.

21221112001212 is an abundant number, since it is smaller than the sum of its proper divisors (34793670358324).

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

21221112001212 is a wasteful number, since it uses less digits than its factorization.

21221112001212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 635895840 (or 635895829 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21221112001212 its reverse (21210021112212), we get a palindrome (42431133113424).

The spelling of 21221112001212 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred twelve million, one thousand, two hundred twelve".