399639263 has 2 divisors, whose sum is σ = 399639264. Its totient is φ = 399639262.

The previous prime is 399639241. The next prime is 399639269. The reversal of 399639263 is 362936993.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 399639263 - 2⁶ = 399639199 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (399639269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199819631 + 199819632.

It is an arithmetic number, because the mean of its divisors is an integer number (199819632).

Almost surely, 2^399639263 is an apocalyptic number.

399639263 is a deficient number, since it is larger than the sum of its proper divisors (1).

399639263 is an equidigital number, since it uses as much as digits as its factorization.

399639263 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1417176, while the sum is 50.

The square root of 399639263 is about 19990.9795407829. The cubic root of 399639263 is about 736.5847386986.

The spelling of 399639263 in words is "three hundred ninety-nine million, six hundred thirty-nine thousand, two hundred sixty-three".