21131302312 has 16 divisors (see below), whose sum is σ = 40270720500. Its totient is φ = 10392443520.

The previous prime is 21131302267. The next prime is 21131302321. The reversal of 21131302312 is 21320313112.

It can be written as a sum of positive squares in 2 ways, for example, as 16344599716 + 4786702596 = 127846^2 + 69186^2 .

It is a super-2 number, since 2×21131302312² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21131302312.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21650437 + ... + 21651412.

Almost surely, 2^21131302312 is an apocalyptic number.

It is an amenable number.

21131302312 is a deficient number, since it is larger than the sum of its proper divisors (19139418188).

21131302312 is a wasteful number, since it uses less digits than its factorization.

21131302312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43301916 (or 43301912 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 21131302312 its reverse (21320313112), we get a palindrome (42451615424).

The spelling of 21131302312 in words is "twenty-one billion, one hundred thirty-one million, three hundred two thousand, three hundred twelve".