399911231 has 2 divisors, whose sum is σ = 399911232. Its totient is φ = 399911230.

The previous prime is 399911227. The next prime is 399911233. The reversal of 399911231 is 132119993.

It is a strong prime.

It is an emirp because it is prime and its reverse (132119993) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 399911231 - 2² = 399911227 is a prime.

It is a super-2 number, since 2×399911231² = 319857985359870722, which contains 22 as substring.

Together with 399911233, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (399911233) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199955615 + 199955616.

It is an arithmetic number, because the mean of its divisors is an integer number (199955616).

Almost surely, 2^399911231 is an apocalyptic number.

399911231 is a deficient number, since it is larger than the sum of its proper divisors (1).

399911231 is an equidigital number, since it uses as much as digits as its factorization.

399911231 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13122, while the sum is 38.

The square root of 399911231 is about 19997.7806518623. The cubic root of 399911231 is about 736.7517910636.

The spelling of 399911231 in words is "three hundred ninety-nine million, nine hundred eleven thousand, two hundred thirty-one".