21724590356 has 48 divisors (see below), whose sum is σ = 43871103360. Its totient is φ = 9220270080.

The previous prime is 21724590331. The next prime is 21724590379. The reversal of 21724590356 is 65309542712.

It is a super-2 number, since 2×21724590356² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5120396 + ... + 5124636.

It is an arithmetic number, because the mean of its divisors is an integer number (913981320).

Almost surely, 2^21724590356 is an apocalyptic number.

It is an amenable number.

21724590356 is an abundant number, since it is smaller than the sum of its proper divisors (22146513004).

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

21724590356 is a wasteful number, since it uses less digits than its factorization.

21724590356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5984 (or 5982 counting only the distinct ones).

The product of its (nonzero) digits is 453600, while the sum is 44.

The spelling of 21724590356 in words is "twenty-one billion, seven hundred twenty-four million, five hundred ninety thousand, three hundred fifty-six".