399887911 has 2 divisors, whose sum is σ = 399887912. Its totient is φ = 399887910.

The previous prime is 399887909. The next prime is 399887933. The reversal of 399887911 is 119788993.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 399887911 - 2¹ = 399887909 is a prime.

Together with 399887909, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (399887981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199943955 + 199943956.

It is an arithmetic number, because the mean of its divisors is an integer number (199943956).

Almost surely, 2^399887911 is an apocalyptic number.

399887911 is a deficient number, since it is larger than the sum of its proper divisors (1).

399887911 is an equidigital number, since it uses as much as digits as its factorization.

399887911 is an evil number, because the sum of its binary digits is even.

The product of its digits is 979776, while the sum is 55.

The square root of 399887911 is about 19997.1975786609. The cubic root of 399887911 is about 736.7374700640.

The spelling of 399887911 in words is "three hundred ninety-nine million, eight hundred eighty-seven thousand, nine hundred eleven".