397891 has 8 divisors (see below), whose sum is σ = 433664. Its totient is φ = 362880.

The previous prime is 397867. The next prime is 397897. The reversal of 397891 is 198793.

397891 is nontrivially palindromic in base 2.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 397891 - 2⁷ = 397763 is a prime.

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 397891.

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

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 in 7 ways as a sum of consecutive naturals, for example, 1531 + ... + 1771.

It is an arithmetic number, because the mean of its divisors is an integer number (54208).

2³⁹⁷⁸⁹¹ is an apocalyptic number.

397891 is a deficient number, since it is larger than the sum of its proper divisors (35773).

397891 is a wasteful number, since it uses less digits than its factorization.

397891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 381.

The product of its digits is 13608, while the sum is 37.

The square root of 397891 is about 630.7860176003. The cubic root of 397891 is about 73.5509080115.

The spelling of 397891 in words is "three hundred ninety-seven thousand, eight hundred ninety-one".