391656 has 16 divisors (see below), whose sum is σ = 979200. Its totient is φ = 130544.

The previous prime is 391639. The next prime is 391661. The reversal of 391656 is 656193.

It is a happy number.

It is an unprimeable number.

391656 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, 8136 + ... + 8183.

It is an arithmetic number, because the mean of its divisors is an integer number (61200).

2³⁹¹⁶⁵⁶ is an apocalyptic number.

It is an amenable number.

391656 is an abundant number, since it is smaller than the sum of its proper divisors (587544).

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

391656 is a wasteful number, since it uses less digits than its factorization.

391656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16328 (or 16324 counting only the distinct ones).

The product of its digits is 4860, while the sum is 30.

The square root of 391656 is about 625.8242564810. The cubic root of 391656 is about 73.1646997521.

The spelling of 391656 in words is "three hundred ninety-one thousand, six hundred fifty-six".