399803717 has 4 divisors (see below), whose sum is σ = 399942060. Its totient is φ = 399665376.

The previous prime is 399803713. The next prime is 399803737. The reversal of 399803717 is 717308993.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 322346116 + 77457601 = 17954^2 + 8801^2 .

It is a cyclic number.

It is not a de Polignac number, because 399803717 - 2² = 399803713 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399803713) 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, 64742 + ... + 70647.

It is an arithmetic number, because the mean of its divisors is an integer number (99985515).

Almost surely, 2^399803717 is an apocalyptic number.

It is an amenable number.

399803717 is a deficient number, since it is larger than the sum of its proper divisors (138343).

399803717 is a wasteful number, since it uses less digits than its factorization.

399803717 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138342.

The product of its (nonzero) digits is 285768, while the sum is 47.

The square root of 399803717 is about 19995.0923228676. The cubic root of 399803717 is about 736.6857612171.

The spelling of 399803717 in words is "three hundred ninety-nine million, eight hundred three thousand, seven hundred seventeen".