399196691 has 4 divisors (see below), whose sum is σ = 399236712. Its totient is φ = 399156672.

The previous prime is 399196667. The next prime is 399196697. The reversal of 399196691 is 196691993.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-399196691 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399196697) 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, 8360 + ... + 29466.

It is an arithmetic number, because the mean of its divisors is an integer number (99809178).

Almost surely, 2^399196691 is an apocalyptic number.

399196691 is a deficient number, since it is larger than the sum of its proper divisors (40021).

399196691 is a wasteful number, since it uses less digits than its factorization.

399196691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40020.

The product of its digits is 708588, while the sum is 53.

The square root of 399196691 is about 19979.9071819666. The cubic root of 399196691 is about 736.3127332319.

The spelling of 399196691 in words is "three hundred ninety-nine million, one hundred ninety-six thousand, six hundred ninety-one".