21285797192925 has 48 divisors (see below), whose sum is σ = 36163878875520. Its totient is φ = 11039426115840.

The previous prime is 21285797192921. The next prime is 21285797192929. The reversal of 21285797192925 is 52929179758212.

It is an interprime number because it is at equal distance from previous prime (21285797192921) and next prime (21285797192929).

It is not a de Polignac number, because 21285797192925 - 2² = 21285797192921 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21285797192925.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21285797192921) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2820664 + ... + 7108286.

It is an arithmetic number, because the mean of its divisors is an integer number (753414143240).

Almost surely, 2^{21285797192925} is an apocalyptic number.

21285797192925 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21285797192925 is a deficient number, since it is larger than the sum of its proper divisors (14878081682595).

21285797192925 is a wasteful number, since it uses less digits than its factorization.

21285797192925 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4289462 (or 4289457 counting only the distinct ones).

The product of its digits is 114307200, while the sum is 69.

The spelling of 21285797192925 in words is "twenty-one trillion, two hundred eighty-five billion, seven hundred ninety-seven million, one hundred ninety-two thousand, nine hundred twenty-five".