399630691 has 4 divisors (see below), whose sum is σ = 408924472. Its totient is φ = 390336912.

The previous prime is 399630677. The next prime is 399630719. The reversal of 399630691 is 196036993.

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

It is a cyclic number.

It is not a de Polignac number, because 399630691 - 2⁷ = 399630563 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399630601) 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, 4646826 + ... + 4646911.

It is an arithmetic number, because the mean of its divisors is an integer number (102231118).

Almost surely, 2^399630691 is an apocalyptic number.

399630691 is a deficient number, since it is larger than the sum of its proper divisors (9293781).

399630691 is an equidigital number, since it uses as much as digits as its factorization.

399630691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9293780.

The product of its (nonzero) digits is 236196, while the sum is 46.

The square root of 399630691 is about 19990.7651429354. The cubic root of 399630691 is about 736.5794722411.

The spelling of 399630691 in words is "three hundred ninety-nine million, six hundred thirty thousand, six hundred ninety-one".