666565025 has 24 divisors (see below), whose sum is σ = 948629760. Its totient is φ = 455132160.

The previous prime is 666565013. The next prime is 666565099. The reversal of 666565025 is 520565666.

It is not a de Polignac number, because 666565025 - 2¹⁸ = 666302881 is a prime.

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, 33857 + ... + 49793.

It is an arithmetic number, because the mean of its divisors is an integer number (39526240).

Almost surely, 2^666565025 is an apocalyptic number.

It is an amenable number.

666565025 is a deficient number, since it is larger than the sum of its proper divisors (282064735).

666565025 is a wasteful number, since it uses less digits than its factorization.

666565025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16193 (or 16188 counting only the distinct ones).

The product of its (nonzero) digits is 324000, while the sum is 41.

The square root of 666565025 is about 25817.9206172767. The cubic root of 666565025 is about 873.5360663927.

The spelling of 666565025 in words is "six hundred sixty-six million, five hundred sixty-five thousand, twenty-five".