21164522425 has 12 divisors (see below), whose sum is σ = 26489282256. Its totient is φ = 16773376400.

The previous prime is 21164522417. The next prime is 21164522437. The reversal of 21164522425 is 52422546112.

It is not a de Polignac number, because 21164522425 - 2³ = 21164522417 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3953311 + ... + 3958660.

It is an arithmetic number, because the mean of its divisors is an integer number (2207440188).

Almost surely, 2^21164522425 is an apocalyptic number.

21164522425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21164522425 is a deficient number, since it is larger than the sum of its proper divisors (5324759831).

21164522425 is a wasteful number, since it uses less digits than its factorization.

21164522425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7912088 (or 7912083 counting only the distinct ones).

The product of its digits is 38400, while the sum is 34.

The spelling of 21164522425 in words is "twenty-one billion, one hundred sixty-four million, five hundred twenty-two thousand, four hundred twenty-five".