21365025134172 has 48 divisors (see below), whose sum is σ = 50033602792992. Its totient is φ = 7095694510080.

The previous prime is 21365025134113. The next prime is 21365025134221. The reversal of 21365025134172 is 27143152056312.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 99190272 + ... + 99405432.

It is an arithmetic number, because the mean of its divisors is an integer number (1042366724854).

Almost surely, 2^{21365025134172} is an apocalyptic number.

It is an amenable number.

21365025134172 is an abundant number, since it is smaller than the sum of its proper divisors (28668577658820).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21365025134172 is a wasteful number, since it uses less digits than its factorization.

21365025134172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 245318 (or 245316 counting only the distinct ones).

The product of its (nonzero) digits is 302400, while the sum is 42.

The spelling of 21365025134172 in words is "twenty-one trillion, three hundred sixty-five billion, twenty-five million, one hundred thirty-four thousand, one hundred seventy-two".