21021112111212 has 36 divisors (see below), whose sum is σ = 53138423561496. Its totient is φ = 7006810095360.

The previous prime is 21021112111177. The next prime is 21021112111247. The reversal of 21021112111212 is 21211121112012.

It is a happy number.

21021112111212 is a `hidden beast` number, since 210 + 21 + 11 + 211 + 1 + 212 = 666.

It is an interprime number because it is at equal distance from previous prime (21021112111177) and next prime (21021112111247).

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×21021112111212² (a number of 27 digits) contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8342638 + ... + 10566069.

Almost surely, 2^{21021112111212} is an apocalyptic number.

It is an amenable number.

21021112111212 is an abundant number, since it is smaller than the sum of its proper divisors (32117311450284).

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

21021112111212 is a wasteful number, since it uses less digits than its factorization.

21021112111212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18939598 (or 18939593 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 21021112111212 its reverse (21211121112012), we get a palindrome (42232233223224).

The spelling of 21021112111212 in words is "twenty-one trillion, twenty-one billion, one hundred twelve million, one hundred eleven thousand, two hundred twelve".