397656 has 64 divisors (see below), whose sum is σ = 1267200. Its totient is φ = 113184.

The previous prime is 397643. The next prime is 397673. The reversal of 397656 is 656793.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nialpdrome in base 9.

It is a self number, because there is not a number n which added to its sum of digits gives 397656.

It is a congruent number.

It is an unprimeable number.

397656 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1381 + ... + 1643.

It is an arithmetic number, because the mean of its divisors is an integer number (19800).

2³⁹⁷⁶⁵⁶ is an apocalyptic number.

397656 is a gapful number since it is divisible by the number (36) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 397656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (633600).

397656 is an abundant number, since it is smaller than the sum of its proper divisors (869544).

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

397656 is a wasteful number, since it uses less digits than its factorization.

397656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 285 (or 275 counting only the distinct ones).

The product of its digits is 34020, while the sum is 36.

The square root of 397656 is about 630.5997145575. The cubic root of 397656 is about 73.5364250942.

The spelling of 397656 in words is "three hundred ninety-seven thousand, six hundred fifty-six".