665139528 has 48 divisors (see below), whose sum is σ = 1850113980. Its totient is φ = 215720064.

The previous prime is 665139511. The next prime is 665139529. The reversal of 665139528 is 825931566.

It can be written as a sum of positive squares in 2 ways, for example, as 472540644 + 192598884 = 21738^2 + 13878^2 .

It is not an unprimeable number, because it can be changed into a prime (665139529) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 122175 + ... + 127502.

Almost surely, 2^665139528 is an apocalyptic number.

It is an amenable number.

665139528 is an abundant number, since it is smaller than the sum of its proper divisors (1184974452).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

665139528 is a wasteful number, since it uses less digits than its factorization.

665139528 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 249726 (or 249719 counting only the distinct ones).

The product of its digits is 388800, while the sum is 45.

The square root of 665139528 is about 25790.2991064470. The cubic root of 665139528 is about 872.9129155033.

The spelling of 665139528 in words is "six hundred sixty-five million, one hundred thirty-nine thousand, five hundred twenty-eight".