394971813 has 12 divisors (see below), whose sum is σ = 583783200. Its totient is φ = 257190696.

The previous prime is 394971809. The next prime is 394971833. The reversal of 394971813 is 318179493.

It is not a de Polignac number, because 394971813 - 2² = 394971809 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (394971833) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 509913 + ... + 510686.

It is an arithmetic number, because the mean of its divisors is an integer number (48648600).

Almost surely, 2^394971813 is an apocalyptic number.

It is an amenable number.

394971813 is a deficient number, since it is larger than the sum of its proper divisors (188811387).

394971813 is a wasteful number, since it uses less digits than its factorization.

394971813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1020648 (or 1020645 counting only the distinct ones).

The product of its digits is 163296, while the sum is 45.

The square root of 394971813 is about 19873.8977807576. The cubic root of 394971813 is about 733.7059389992.

The spelling of 394971813 in words is "three hundred ninety-four million, nine hundred seventy-one thousand, eight hundred thirteen".