399651913 has 2 divisors, whose sum is σ = 399651914. Its totient is φ = 399651912.

The previous prime is 399651839. The next prime is 399651937. The reversal of 399651913 is 319156993.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 399520144 + 131769 = 19988^2 + 363^2 .

It is a cyclic number.

It is not a de Polignac number, because 399651913 - 2¹⁷ = 399520841 is a prime.

It is not a weakly prime, because it can be changed into another prime (399651943) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199825956 + 199825957.

It is an arithmetic number, because the mean of its divisors is an integer number (199825957).

Almost surely, 2^399651913 is an apocalyptic number.

It is an amenable number.

399651913 is a deficient number, since it is larger than the sum of its proper divisors (1).

399651913 is an equidigital number, since it uses as much as digits as its factorization.

399651913 is an evil number, because the sum of its binary digits is even.

The product of its digits is 196830, while the sum is 46.

The square root of 399651913 is about 19991.2959309796. The cubic root of 399651913 is about 736.5925104563.

The spelling of 399651913 in words is "three hundred ninety-nine million, six hundred fifty-one thousand, nine hundred thirteen".