397531 has 4 divisors (see below), whose sum is σ = 399064. Its totient is φ = 396000.

The previous prime is 397519. The next prime is 397541. The reversal of 397531 is 135793.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-397531 is a prime.

It is a super-2 number, since 2×397531² = 316061791922, which contains 22 as substring.

It is the 631-st Hogben number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 397531.

It is not an unprimeable number, because it can be changed into a prime (397541) by changing a digit.

It is a nontrivial repunit in base 630.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 270 + ... + 931.

It is an arithmetic number, because the mean of its divisors is an integer number (99766).

2³⁹⁷⁵³¹ is an apocalyptic number.

397531 is a deficient number, since it is larger than the sum of its proper divisors (1533).

397531 is a wasteful number, since it uses less digits than its factorization.

397531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1532.

The product of its digits is 2835, while the sum is 28.

The square root of 397531 is about 630.5005947658. The cubic root of 397531 is about 73.5287190899.

The spelling of 397531 in words is "three hundred ninety-seven thousand, five hundred thirty-one".