666666631225 has 24 divisors (see below), whose sum is σ = 977339856960. Its totient is φ = 441379283520.

The previous prime is 666666631207. The next prime is 666666631229. The reversal of 666666631225 is 522136666666.

It is not a de Polignac number, because 666666631225 - 2⁷ = 666666631097 is a prime.

It is not an unprimeable number, because it can be changed into a prime (666666631229) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 65676367 + ... + 65686516.

It is an arithmetic number, because the mean of its divisors is an integer number (40722494040).

Almost surely, 2^666666631225 is an apocalyptic number.

It is an amenable number.

666666631225 is a deficient number, since it is larger than the sum of its proper divisors (310673225735).

666666631225 is a wasteful number, since it uses less digits than its factorization.

666666631225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131362929 (or 131362924 counting only the distinct ones).

The product of its digits is 16796160, while the sum is 55.

The spelling of 666666631225 in words is "six hundred sixty-six billion, six hundred sixty-six million, six hundred thirty-one thousand, two hundred twenty-five".