665974 has 4 divisors (see below), whose sum is σ = 998964. Its totient is φ = 332986.

The previous prime is 665953. The next prime is 665981. The reversal of 665974 is 479566.

665974 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 479566 = 2 ⋅239783.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166492 + ... + 166495.

It is an arithmetic number, because the mean of its divisors is an integer number (249741).

2⁶⁶⁵⁹⁷⁴ is an apocalyptic number.

665974 is a deficient number, since it is larger than the sum of its proper divisors (332990).

665974 is a wasteful number, since it uses less digits than its factorization.

665974 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332989.

The product of its digits is 45360, while the sum is 37.

The square root of 665974 is about 816.0723007185. The cubic root of 665974 is about 87.3277809858.

The spelling of 665974 in words is "six hundred sixty-five thousand, nine hundred seventy-four".