397993813 has 8 divisors (see below), whose sum is σ = 459540032. Its totient is φ = 337620096.

The previous prime is 397993811. The next prime is 397993873. The reversal of 397993813 is 318399793.

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 397993813 - 2¹ = 397993811 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (397993811) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 292395 + ... + 293752.

It is an arithmetic number, because the mean of its divisors is an integer number (57442504).

Almost surely, 2^397993813 is an apocalyptic number.

It is an amenable number.

397993813 is a deficient number, since it is larger than the sum of its proper divisors (61546219).

397993813 is an equidigital number, since it uses as much as digits as its factorization.

397993813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 586251.

The product of its digits is 1102248, while the sum is 52.

The square root of 397993813 is about 19949.7822795137. The cubic root of 397993813 is about 735.5724252540.

The spelling of 397993813 in words is "three hundred ninety-seven million, nine hundred ninety-three thousand, eight hundred thirteen".