21052540125 has 48 divisors (see below), whose sum is σ = 37968905520. Its totient is φ = 11222640000.

The previous prime is 21052540109. The next prime is 21052540133. The reversal of 21052540125 is 52104525012.

21052540125 is a `hidden beast` number, since 2 + 10 + 525 + 4 + 0 + 125 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 12888152676 + 8164387449 = 113526^2 + 90357^2 .

It is not a de Polignac number, because 21052540125 - 2⁴ = 21052540109 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3710791 + ... + 3716459.

It is an arithmetic number, because the mean of its divisors is an integer number (791018865).

Almost surely, 2^21052540125 is an apocalyptic number.

21052540125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21052540125 is a deficient number, since it is larger than the sum of its proper divisors (16916365395).

21052540125 is a wasteful number, since it uses less digits than its factorization.

21052540125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8991 (or 8978 counting only the distinct ones).

The product of its (nonzero) digits is 4000, while the sum is 27.

The spelling of 21052540125 in words is "twenty-one billion, fifty-two million, five hundred forty thousand, one hundred twenty-five".