397920 has 48 divisors (see below), whose sum is σ = 1254960. Its totient is φ = 105984.

The previous prime is 397907. The next prime is 397921. The reversal of 397920 is 29793.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (397921) by changing a digit.

397920 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 7 ways as a sum of consecutive naturals, for example, 66 + ... + 894.

It is an arithmetic number, because the mean of its divisors is an integer number (26145).

2³⁹⁷⁹²⁰ is an apocalyptic number.

397920 is a gapful number since it is divisible by the number (30) 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 397920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (627480).

397920 is an abundant number, since it is smaller than the sum of its proper divisors (857040).

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

397920 is a wasteful number, since it uses less digits than its factorization.

397920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 847 (or 839 counting only the distinct ones).

The product of its (nonzero) digits is 3402, while the sum is 30.

The square root of 397920 is about 630.8090043745. The cubic root of 397920 is about 73.5526948698.

The spelling of 397920 in words is "three hundred ninety-seven thousand, nine hundred twenty".