21604484775 has 24 divisors (see below), whose sum is σ = 37272435840. Its totient is φ = 11021417440.

The previous prime is 21604484771. The next prime is 21604484819. The reversal of 21604484775 is 57748440612.

It is not a de Polignac number, because 21604484775 - 2² = 21604484771 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21604484771) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6260445 + ... + 6263894.

It is an arithmetic number, because the mean of its divisors is an integer number (1553018160).

Almost surely, 2^21604484775 is an apocalyptic number.

21604484775 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21604484775 is a deficient number, since it is larger than the sum of its proper divisors (15667951065).

21604484775 is a wasteful number, since it uses less digits than its factorization.

21604484775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12524375 (or 12524370 counting only the distinct ones).

The product of its (nonzero) digits is 1505280, while the sum is 48.

The spelling of 21604484775 in words is "twenty-one billion, six hundred four million, four hundred eighty-four thousand, seven hundred seventy-five".