21945763512 has 56 divisors (see below), whose sum is σ = 61694253840. Its totient is φ = 7315252560.

The previous prime is 21945763507. The next prime is 21945763547. The reversal of 21945763512 is 21536754912.

21945763512 is a `hidden beast` number, since 2 + 1 + 9 + 4 + 5 + 7 + 635 + 1 + 2 = 666.

It is a super-2 number, since 2×21945763512² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 1875664 + ... + 1887327.

Almost surely, 2^21945763512 is an apocalyptic number.

It is an amenable number.

21945763512 is an abundant number, since it is smaller than the sum of its proper divisors (39748490328).

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

21945763512 is an equidigital number, since it uses as much as digits as its factorization.

21945763512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3763015 (or 3762996 counting only the distinct ones).

The product of its digits is 453600, while the sum is 45.

The spelling of 21945763512 in words is "twenty-one billion, nine hundred forty-five million, seven hundred sixty-three thousand, five hundred twelve".