21120331212 has 18 divisors (see below), whose sum is σ = 53387503988. Its totient is φ = 7040110392.

The previous prime is 21120331171. The next prime is 21120331223. The reversal of 21120331212 is 21213302112.

21120331212 is a `hidden beast` number, since 2 + 1 + 120 + 331 + 212 = 666.

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-3 number, since 3×21120331212³ (a number of 32 digits) contains 333 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 5 ways as a sum of consecutive naturals, for example, 293337898 + ... + 293337969.

Almost surely, 2^21120331212 is an apocalyptic number.

It is an amenable number.

21120331212 is an abundant number, since it is smaller than the sum of its proper divisors (32267172776).

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

21120331212 is a wasteful number, since it uses less digits than its factorization.

21120331212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 586675877 (or 586675872 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21120331212 its reverse (21213302112), we get a palindrome (42333633324).

The spelling of 21120331212 in words is "twenty-one billion, one hundred twenty million, three hundred thirty-one thousand, two hundred twelve".