21152531531025 has 36 divisors (see below), whose sum is σ = 37915745674092. Its totient is φ = 11272651960320.

The previous prime is 21152531530969. The next prime is 21152531531041. The reversal of 21152531531025 is 52013513525112.

21152531531025 is a `hidden beast` number, since 2 + 1 + 1 + 5 + 2 + 5 + 315 + 310 + 25 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 4445046955584 + 16707484575441 = 2108328^2 + 4087479^2 .

It is not a de Polignac number, because 21152531531025 - 2¹¹ = 21152531528977 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 35949984 + ... + 36533633.

Almost surely, 2^{21152531531025} is an apocalyptic number.

21152531531025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21152531531025 is a deficient number, since it is larger than the sum of its proper divisors (16763214143067).

21152531531025 is a wasteful number, since it uses less digits than its factorization.

21152531531025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72484930 (or 72484922 counting only the distinct ones).

The product of its (nonzero) digits is 45000, while the sum is 36.

The spelling of 21152531531025 in words is "twenty-one trillion, one hundred fifty-two billion, five hundred thirty-one million, five hundred thirty-one thousand, twenty-five".