397992861 has 24 divisors (see below), whose sum is σ = 666011840. Its totient is φ = 224306496.

The previous prime is 397992841. The next prime is 397992871. The reversal of 397992861 is 168299793.

It is not a de Polignac number, because 397992861 - 2⁷ = 397992733 is a prime.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 397992798 and 397992807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (397992841) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 38671 + ... + 47868.

Almost surely, 2^397992861 is an apocalyptic number.

It is an amenable number.

397992861 is a deficient number, since it is larger than the sum of its proper divisors (268018979).

397992861 is a wasteful number, since it uses less digits than its factorization.

397992861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86625 (or 86622 counting only the distinct ones).

The product of its digits is 1469664, while the sum is 54.

The square root of 397992861 is about 19949.7584195899. The cubic root of 397992861 is about 735.5718387579.

The spelling of 397992861 in words is "three hundred ninety-seven million, nine hundred ninety-two thousand, eight hundred sixty-one".