20125165657 has 4 divisors (see below), whose sum is σ = 20125459620. Its totient is φ = 20124871696.

The previous prime is 20125165651. The next prime is 20125165661. The reversal of 20125165657 is 75656152102.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 10240630416 + 9884535241 = 101196^2 + 99421^2 .

It is a cyclic number.

It is not a de Polignac number, because 20125165657 - 2²⁷ = 19990947929 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20125165651) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15819 + ... + 201247.

It is an arithmetic number, because the mean of its divisors is an integer number (5031364905).

Almost surely, 2^20125165657 is an apocalyptic number.

It is an amenable number.

20125165657 is a deficient number, since it is larger than the sum of its proper divisors (293963).

20125165657 is a wasteful number, since it uses less digits than its factorization.

20125165657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 293962.

The product of its (nonzero) digits is 126000, while the sum is 40.

The spelling of 20125165657 in words is "twenty billion, one hundred twenty-five million, one hundred sixty-five thousand, six hundred fifty-seven".