397315993 has 4 divisors (see below), whose sum is σ = 420687540. Its totient is φ = 373944448.

The previous prime is 397315987. The next prime is 397315999. The reversal of 397315993 is 399513793.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (397315987) and next prime (397315999).

It can be written as a sum of positive squares in 2 ways, for example, as 357474649 + 39841344 = 18907^2 + 6312^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-397315993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (397315999) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11685748 + ... + 11685781.

It is an arithmetic number, because the mean of its divisors is an integer number (105171885).

Almost surely, 2^397315993 is an apocalyptic number.

It is an amenable number.

397315993 is a deficient number, since it is larger than the sum of its proper divisors (23371547).

397315993 is a wasteful number, since it uses less digits than its factorization.

397315993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23371546.

The product of its digits is 688905, while the sum is 49.

The square root of 397315993 is about 19932.7868849291. The cubic root of 397315993 is about 735.1546055134.

The spelling of 397315993 in words is "three hundred ninety-seven million, three hundred fifteen thousand, nine hundred ninety-three".