21604736440057 has 16 divisors (see below), whose sum is σ = 22783587360768. Its totient is φ = 20446208917200.

The previous prime is 21604736439917. The next prime is 21604736440097. The reversal of 21604736440057 is 75004463740612.

It is a cyclic number.

It is not a de Polignac number, because 21604736440057 - 2⁴³ = 12808643417849 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21604736440097) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1521069 + ... + 6747082.

It is an arithmetic number, because the mean of its divisors is an integer number (1423974210048).

Almost surely, 2^{21604736440057} is an apocalyptic number.

It is an amenable number.

21604736440057 is a deficient number, since it is larger than the sum of its proper divisors (1178850920711).

21604736440057 is a wasteful number, since it uses less digits than its factorization.

21604736440057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8269380.

The product of its (nonzero) digits is 3386880, while the sum is 49.

The spelling of 21604736440057 in words is "twenty-one trillion, six hundred four billion, seven hundred thirty-six million, four hundred forty thousand, fifty-seven".