21731064544 has 48 divisors (see below), whose sum is σ = 48919248000. Its totient is φ = 9308674944.

The previous prime is 21731064529. The next prime is 21731064577. The reversal of 21731064544 is 44546013712.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 447067 + ... + 493285.

It is an arithmetic number, because the mean of its divisors is an integer number (1019151000).

Almost surely, 2^21731064544 is an apocalyptic number.

It is an amenable number.

21731064544 is an abundant number, since it is smaller than the sum of its proper divisors (27188183456).

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

21731064544 is a wasteful number, since it uses less digits than its factorization.

21731064544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48335 (or 48327 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 37.

The spelling of 21731064544 in words is "twenty-one billion, seven hundred thirty-one million, sixty-four thousand, five hundred forty-four".