665972 has 12 divisors (see below), whose sum is σ = 1171296. Its totient is φ = 331320.

The previous prime is 665953. The next prime is 665981. The reversal of 665972 is 279566.

It is a plaindrome in base 9.

It is a congruent number.

It is an unprimeable number.

665972 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1073 + ... + 1575.

It is an arithmetic number, because the mean of its divisors is an integer number (97608).

2⁶⁶⁵⁹⁷² is an apocalyptic number.

It is an amenable number.

665972 is a deficient number, since it is larger than the sum of its proper divisors (505324).

665972 is a wasteful number, since it uses less digits than its factorization.

665972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 838 (or 836 counting only the distinct ones).

The product of its digits is 22680, while the sum is 35.

The square root of 665972 is about 816.0710753360. The cubic root of 665972 is about 87.3276935671.

The spelling of 665972 in words is "six hundred sixty-five thousand, nine hundred seventy-two".