399517903 has 4 divisors (see below), whose sum is σ = 399560368. Its totient is φ = 399475440.

The previous prime is 399517879. The next prime is 399517919. The reversal of 399517903 is 309715993.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 309715993 = 3229 ⋅95917.

It is a cyclic number.

It is not a de Polignac number, because 399517903 - 2⁵ = 399517871 is a prime.

It is a super-2 number, since 2×399517903² = 319229109635034818, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399517973) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 126 + ... + 28267.

It is an arithmetic number, because the mean of its divisors is an integer number (99890092).

Almost surely, 2^399517903 is an apocalyptic number.

399517903 is a deficient number, since it is larger than the sum of its proper divisors (42465).

399517903 is a wasteful number, since it uses less digits than its factorization.

399517903 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42464.

The product of its (nonzero) digits is 229635, while the sum is 46.

The square root of 399517903 is about 19987.9439412862. The cubic root of 399517903 is about 736.5101706382.

The spelling of 399517903 in words is "three hundred ninety-nine million, five hundred seventeen thousand, nine hundred three".