21618272401 has 32 divisors (see below), whose sum is σ = 25710462720. Its totient is φ = 17969952000.

The previous prime is 21618272399. The next prime is 21618272441. The reversal of 21618272401 is 10427281612.

It is not a de Polignac number, because 21618272401 - 2¹ = 21618272399 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21618272441) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 726451 + ... + 755623.

It is an arithmetic number, because the mean of its divisors is an integer number (803451960).

Almost surely, 2^21618272401 is an apocalyptic number.

It is an amenable number.

21618272401 is a deficient number, since it is larger than the sum of its proper divisors (4092190319).

21618272401 is a wasteful number, since it uses less digits than its factorization.

21618272401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29337.

The product of its (nonzero) digits is 10752, while the sum is 34.

The spelling of 21618272401 in words is "twenty-one billion, six hundred eighteen million, two hundred seventy-two thousand, four hundred one".