399600031 has 4 divisors (see below), whose sum is σ = 400117752. Its totient is φ = 399082312.

The previous prime is 399600017. The next prime is 399600043. The reversal of 399600031 is 130006993.

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 399600031 - 2¹³ = 399591839 is a prime.

It is a super-2 number, since 2×399600031² = 319360369550401922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 399599966 and 399600002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399600631) 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, 257701 + ... + 259246.

It is an arithmetic number, because the mean of its divisors is an integer number (100029438).

Almost surely, 2^399600031 is an apocalyptic number.

399600031 is a deficient number, since it is larger than the sum of its proper divisors (517721).

399600031 is an equidigital number, since it uses as much as digits as its factorization.

399600031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 517720.

The product of its (nonzero) digits is 4374, while the sum is 31.

The square root of 399600031 is about 19989.9982741370. The cubic root of 399600031 is about 736.5606347622.

The spelling of 399600031 in words is "three hundred ninety-nine million, six hundred thousand, thirty-one".