397890 has 24 divisors (see below), whose sum is σ = 1034748. Its totient is φ = 106080.

The previous prime is 397867. The next prime is 397897. The reversal of 397890 is 98793.

It can be written as a sum of positive squares in 2 ways, for example, as 393129 + 4761 = 627^2 + 69^2 .

It is not an unprimeable number, because it can be changed into a prime (397897) by changing a digit.

397890 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 11 ways as a sum of consecutive naturals, for example, 2121 + ... + 2300.

2³⁹⁷⁸⁹⁰ is an apocalyptic number.

397890 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

397890 is an abundant number, since it is smaller than the sum of its proper divisors (636858).

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

397890 is a wasteful number, since it uses less digits than its factorization.

397890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4434 (or 4431 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 36.

The square root of 397890 is about 630.7852249379. The cubic root of 397890 is about 73.5508463941.

The spelling of 397890 in words is "three hundred ninety-seven thousand, eight hundred ninety".