399933643 has 2 divisors, whose sum is σ = 399933644. Its totient is φ = 399933642.

The previous prime is 399933607. The next prime is 399933659. The reversal of 399933643 is 346339993.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-399933643 is a prime.

It is not a weakly prime, because it can be changed into another prime (399933673) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199966821 + 199966822.

It is an arithmetic number, because the mean of its divisors is an integer number (199966822).

Almost surely, 2^399933643 is an apocalyptic number.

399933643 is a deficient number, since it is larger than the sum of its proper divisors (1).

399933643 is an equidigital number, since it uses as much as digits as its factorization.

399933643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1417176, while the sum is 49.

The square root of 399933643 is about 19998.3410061935. The cubic root of 399933643 is about 736.7655539285.

The spelling of 399933643 in words is "three hundred ninety-nine million, nine hundred thirty-three thousand, six hundred forty-three".