665904674 has 4 divisors (see below), whose sum is σ = 998857014. Its totient is φ = 332952336.

The previous prime is 665904623. The next prime is 665904689. The reversal of 665904674 is 476409566.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 476409566 = 2 ⋅238204783.

It can be written as a sum of positive squares in only one way, i.e., 479391025 + 186513649 = 21895^2 + 13657^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166476167 + ... + 166476170.

Almost surely, 2^665904674 is an apocalyptic number.

665904674 is a deficient number, since it is larger than the sum of its proper divisors (332952340).

665904674 is a wasteful number, since it uses less digits than its factorization.

665904674 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332952339.

The product of its (nonzero) digits is 1088640, while the sum is 47.

The square root of 665904674 is about 25805.1288313002. The cubic root of 665904674 is about 873.2475068944.

The spelling of 665904674 in words is "six hundred sixty-five million, nine hundred four thousand, six hundred seventy-four".