21604888271 has 4 divisors (see below), whose sum is σ = 21909182544. Its totient is φ = 21300594000.

The previous prime is 21604888259. The next prime is 21604888367. The reversal of 21604888271 is 17288840612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21604888271 - 2¹⁰ = 21604887247 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21604888211) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 152147030 + ... + 152147171.

It is an arithmetic number, because the mean of its divisors is an integer number (5477295636).

Almost surely, 2^21604888271 is an apocalyptic number.

21604888271 is a deficient number, since it is larger than the sum of its proper divisors (304294273).

21604888271 is an equidigital number, since it uses as much as digits as its factorization.

21604888271 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 304294272.

The product of its (nonzero) digits is 344064, while the sum is 47.

The spelling of 21604888271 in words is "twenty-one billion, six hundred four million, eight hundred eighty-eight thousand, two hundred seventy-one".