399766889 has 2 divisors, whose sum is σ = 399766890. Its totient is φ = 399766888.

The previous prime is 399766879. The next prime is 399766891. The reversal of 399766889 is 988667993.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 346257664 + 53509225 = 18608^2 + 7315^2 .

It is a cyclic number.

It is not a de Polignac number, because 399766889 - 2²⁸ = 131331433 is a prime.

Together with 399766891, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (399766879) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199883444 + 199883445.

It is an arithmetic number, because the mean of its divisors is an integer number (199883445).

Almost surely, 2^399766889 is an apocalyptic number.

It is an amenable number.

399766889 is a deficient number, since it is larger than the sum of its proper divisors (1).

399766889 is an equidigital number, since it uses as much as digits as its factorization.

399766889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 35271936, while the sum is 65.

The square root of 399766889 is about 19994.1713756785. The cubic root of 399766889 is about 736.6631405367.

The spelling of 399766889 in words is "three hundred ninety-nine million, seven hundred sixty-six thousand, eight hundred eighty-nine".