21455515355504 has 40 divisors (see below), whose sum is σ = 43116284958528. Its totient is φ = 10334473516800.

The previous prime is 21455515355501. The next prime is 21455515355563. The reversal of 21455515355504 is 40555351555412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21455515355501) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 179358152 + ... + 179477735.

Almost surely, 2^{21455515355504} is an apocalyptic number.

It is an amenable number.

21455515355504 is an abundant number, since it is smaller than the sum of its proper divisors (21660769603024).

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

21455515355504 is a wasteful number, since it uses less digits than its factorization.

21455515355504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 358836033 (or 358836027 counting only the distinct ones).

The product of its (nonzero) digits is 7500000, while the sum is 50.

The spelling of 21455515355504 in words is "twenty-one trillion, four hundred fifty-five billion, five hundred fifteen million, three hundred fifty-five thousand, five hundred four".