21731286312 has 32 divisors (see below), whose sum is σ = 60364684800. Its totient is φ = 7243762032.

The previous prime is 21731286301. The next prime is 21731286359. The reversal of 21731286312 is 21368213712.

21731286312 is a `hidden beast` number, since 2 + 1 + 7 + 3 + 12 + 8 + 631 + 2 = 666.

It is a super-2 number, since 2×21731286312² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 50303688 + ... + 50304119.

It is an arithmetic number, because the mean of its divisors is an integer number (1886396400).

Almost surely, 2^21731286312 is an apocalyptic number.

It is an amenable number.

21731286312 is an abundant number, since it is smaller than the sum of its proper divisors (38633398488).

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

21731286312 is a wasteful number, since it uses less digits than its factorization.

21731286312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100607822 (or 100607812 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The spelling of 21731286312 in words is "twenty-one billion, seven hundred thirty-one million, two hundred eighty-six thousand, three hundred twelve".