21164264522025 has 24 divisors (see below), whose sum is σ = 35009705214624. Its totient is φ = 11281762195200.

The previous prime is 21164264522021. The next prime is 21164264522033. The reversal of 21164264522025 is 52022546246112.

It is a happy number.

It is not a de Polignac number, because 21164264522025 - 2² = 21164264522021 is a prime.

It is a super-2 number, since 2×21164264522025² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21164264522021) 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, 72923584 + ... + 73213233.

It is an arithmetic number, because the mean of its divisors is an integer number (1458737717276).

Almost surely, 2^{21164264522025} is an apocalyptic number.

21164264522025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21164264522025 is a deficient number, since it is larger than the sum of its proper divisors (13845440692599).

21164264522025 is a wasteful number, since it uses less digits than its factorization.

21164264522025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146138761 (or 146138756 counting only the distinct ones).

The product of its (nonzero) digits is 460800, while the sum is 42.

The spelling of 21164264522025 in words is "twenty-one trillion, one hundred sixty-four billion, two hundred sixty-four million, five hundred twenty-two thousand, twenty-five".