397820 has 12 divisors (see below), whose sum is σ = 835464. Its totient is φ = 159120.

The previous prime is 397811. The next prime is 397829. The reversal of 397820 is 28793.

It is an interprime number because it is at equal distance from previous prime (397811) and next prime (397829).

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 397820.

It is not an unprimeable number, because it can be changed into a prime (397829) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9926 + ... + 9965.

It is an arithmetic number, because the mean of its divisors is an integer number (69622).

2³⁹⁷⁸²⁰ is an apocalyptic number.

It is an amenable number.

397820 is an abundant number, since it is smaller than the sum of its proper divisors (437644).

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

397820 is a wasteful number, since it uses less digits than its factorization.

397820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19900 (or 19898 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 397820 is about 630.7297360994. The cubic root of 397820 is about 73.5465329229.

The spelling of 397820 in words is "three hundred ninety-seven thousand, eight hundred twenty".