21506253261325 has 48 divisors (see below), whose sum is σ = 30591601119360. Its totient is φ = 14691957477120.

The previous prime is 21506253261299. The next prime is 21506253261331. The reversal of 21506253261325 is 52316235260512.

It is not a de Polignac number, because 21506253261325 - 2¹¹ = 21506253259277 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 94693354 + ... + 94920196.

It is an arithmetic number, because the mean of its divisors is an integer number (637325023320).

Almost surely, 2^{21506253261325} is an apocalyptic number.

21506253261325 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21506253261325 is a deficient number, since it is larger than the sum of its proper divisors (9085347858035).

21506253261325 is a wasteful number, since it uses less digits than its factorization.

21506253261325 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 228886 (or 228881 counting only the distinct ones).

The product of its (nonzero) digits is 648000, while the sum is 43.

The spelling of 21506253261325 in words is "twenty-one trillion, five hundred six billion, two hundred fifty-three million, two hundred sixty-one thousand, three hundred twenty-five".