397988 has 6 divisors (see below), whose sum is σ = 696486. Its totient is φ = 198992.

The previous prime is 397981. The next prime is 398011. The reversal of 397988 is 889793.

It can be written as a sum of positive squares in only one way, i.e., 350464 + 47524 = 592^2 + 218^2 .

It is not an unprimeable number, because it can be changed into a prime (397981) by changing a digit.

397988 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49745 + ... + 49752.

It is an arithmetic number, because the mean of its divisors is an integer number (116081).

2³⁹⁷⁹⁸⁸ is an apocalyptic number.

It is an amenable number.

397988 is a deficient number, since it is larger than the sum of its proper divisors (298498).

397988 is a wasteful number, since it uses less digits than its factorization.

397988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99501 (or 99499 counting only the distinct ones).

The product of its digits is 108864, while the sum is 44.

The square root of 397988 is about 630.8629011124. The cubic root of 397988 is about 73.5568844040.

The spelling of 397988 in words is "three hundred ninety-seven thousand, nine hundred eighty-eight".