21990362724 has 72 divisors (see below), whose sum is σ = 60687506880. Its totient is φ = 6658536000.

The previous prime is 21990362623. The next prime is 21990362729. The reversal of 21990362724 is 42726309912.

21990362724 is a `hidden beast` number, since 2 + 19 + 9 + 0 + 3 + 627 + 2 + 4 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 21990362724.

It is not an unprimeable number, because it can be changed into a prime (21990362729) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 501274 + ... + 543374.

It is an arithmetic number, because the mean of its divisors is an integer number (842882040).

Almost surely, 2^21990362724 is an apocalyptic number.

It is an amenable number.

21990362724 is an abundant number, since it is smaller than the sum of its proper divisors (38697144156).

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

21990362724 is a wasteful number, since it uses less digits than its factorization.

21990362724 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43441 (or 43436 counting only the distinct ones).

The product of its (nonzero) digits is 326592, while the sum is 45.

The spelling of 21990362724 in words is "twenty-one billion, nine hundred ninety million, three hundred sixty-two thousand, seven hundred twenty-four".