399287311 has 4 divisors (see below), whose sum is σ = 399357000. Its totient is φ = 399217624.

The previous prime is 399287309. The next prime is 399287321. The reversal of 399287311 is 113782993.

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 399287311 - 2¹ = 399287309 is a prime.

It is a super-2 number, since 2×399287311² = 318860713451221442, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399287321) 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, 25396 + ... + 37993.

It is an arithmetic number, because the mean of its divisors is an integer number (99839250).

Almost surely, 2^399287311 is an apocalyptic number.

399287311 is a deficient number, since it is larger than the sum of its proper divisors (69689).

399287311 is an equidigital number, since it uses as much as digits as its factorization.

399287311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69688.

The product of its digits is 81648, while the sum is 43.

The square root of 399287311 is about 19982.1748315843. The cubic root of 399287311 is about 736.3684447922.

The spelling of 399287311 in words is "three hundred ninety-nine million, two hundred eighty-seven thousand, three hundred eleven".