20321557925 has 24 divisors (see below), whose sum is σ = 25386042600. Its totient is φ = 16136858880.

The previous prime is 20321557891. The next prime is 20321557951. The reversal of 20321557925 is 52975512302.

It can be written as a sum of positive squares in 12 ways, for example, as 16396034209 + 3925523716 = 128047^2 + 62654^2 .

It is not a de Polignac number, because 20321557925 - 2¹⁰ = 20321556901 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1857371 + ... + 1868279.

It is an arithmetic number, because the mean of its divisors is an integer number (1057751775).

Almost surely, 2^20321557925 is an apocalyptic number.

20321557925 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20321557925 is a deficient number, since it is larger than the sum of its proper divisors (5064484675).

20321557925 is a wasteful number, since it uses less digits than its factorization.

20321557925 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11465 (or 11460 counting only the distinct ones).

The product of its (nonzero) digits is 189000, while the sum is 41.

The spelling of 20321557925 in words is "twenty billion, three hundred twenty-one million, five hundred fifty-seven thousand, nine hundred twenty-five".