399903999 has 32 divisors (see below), whose sum is σ = 614473728. Its totient is φ = 229068000.

The previous prime is 399903979. The next prime is 399904009. The reversal of 399903999 is 999309993.

It is not a de Polignac number, because 399903999 - 2⁹ = 399903487 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399903929) 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 in 31 ways as a sum of consecutive naturals, for example, 39444 + ... + 48534.

It is an arithmetic number, because the mean of its divisors is an integer number (19202304).

Almost surely, 2^399903999 is an apocalyptic number.

399903999 is a deficient number, since it is larger than the sum of its proper divisors (214569729).

399903999 is a wasteful number, since it uses less digits than its factorization.

399903999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9179.

The product of its (nonzero) digits is 4782969, while the sum is 60.

The square root of 399903999 is about 19997.5998309797. The cubic root of 399903999 is about 736.7473498938.

The spelling of 399903999 in words is "three hundred ninety-nine million, nine hundred three thousand, nine hundred ninety-nine".