397647 has 24 divisors (see below), whose sum is σ = 640224. Its totient is φ = 236544.

The previous prime is 397643. The next prime is 397673. The reversal of 397647 is 746793.

397647 is a `hidden beast` number, since 3 + 9 + 7 + 647 = 666.

It is not a de Polignac number, because 397647 - 2² = 397643 is a prime.

It is an Ulam number.

397647 is a lucky number.

It is a nialpdrome in base 9.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 397647.

It is not an unprimeable number, because it can be changed into a prime (397643) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3463 + ... + 3575.

It is an arithmetic number, because the mean of its divisors is an integer number (26676).

2³⁹⁷⁶⁴⁷ is an apocalyptic number.

397647 is a deficient number, since it is larger than the sum of its proper divisors (242577).

397647 is a wasteful number, since it uses less digits than its factorization.

397647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159 (or 156 counting only the distinct ones).

The product of its digits is 31752, while the sum is 36.

The square root of 397647 is about 630.5925784530. The cubic root of 397647 is about 73.5358703158.

The spelling of 397647 in words is "three hundred ninety-seven thousand, six hundred forty-seven".