21555254024 has 32 divisors (see below), whose sum is σ = 40530591000. Its totient is φ = 10747141632.

The previous prime is 21555253999. The next prime is 21555254053. The reversal of 21555254024 is 42045255512.

It can be written as a sum of positive squares in 4 ways, for example, as 21324760900 + 230493124 = 146030^2 + 15182^2 .

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, 5592482 + ... + 5596334.

Almost surely, 2^21555254024 is an apocalyptic number.

It is an amenable number.

21555254024 is a deficient number, since it is larger than the sum of its proper divisors (18975336976).

21555254024 is a wasteful number, since it uses less digits than its factorization.

21555254024 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5657 (or 5653 counting only the distinct ones).

The product of its (nonzero) digits is 80000, while the sum is 35.

The spelling of 21555254024 in words is "twenty-one billion, five hundred fifty-five million, two hundred fifty-four thousand, twenty-four".