397916813 has 8 divisors (see below), whose sum is σ = 474534528. Its totient is φ = 326242224.

The previous prime is 397916809. The next prime is 397916863. The reversal of 397916813 is 318619793.

It is a happy number.

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

It is not a de Polignac number, because 397916813 - 2² = 397916809 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (397916863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1235606 + ... + 1235927.

It is an arithmetic number, because the mean of its divisors is an integer number (59316816).

Almost surely, 2^397916813 is an apocalyptic number.

It is an amenable number.

397916813 is a deficient number, since it is larger than the sum of its proper divisors (76617715).

397916813 is a wasteful number, since it uses less digits than its factorization.

397916813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2471563.

The product of its digits is 244944, while the sum is 47.

The square root of 397916813 is about 19947.8523405403. The cubic root of 397916813 is about 735.5249850444.

The spelling of 397916813 in words is "three hundred ninety-seven million, nine hundred sixteen thousand, eight hundred thirteen".