399507739 has 8 divisors (see below), whose sum is σ = 404667360. Its totient is φ = 394363200.

The previous prime is 399507733. The next prime is 399507751. The reversal of 399507739 is 937705993.

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

It is a cyclic number.

It is not a de Polignac number, because 399507739 - 2⁵ = 399507707 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399507733) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55434 + ... + 62224.

It is an arithmetic number, because the mean of its divisors is an integer number (50583420).

Almost surely, 2^399507739 is an apocalyptic number.

399507739 is a deficient number, since it is larger than the sum of its proper divisors (5159621).

399507739 is an equidigital number, since it uses as much as digits as its factorization.

399507739 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7541.

The product of its (nonzero) digits is 1607445, while the sum is 52.

The square root of 399507739 is about 19987.6896864045. The cubic root of 399507739 is about 736.5039248164.

The spelling of 399507739 in words is "three hundred ninety-nine million, five hundred seven thousand, seven hundred thirty-nine".