399907 has 4 divisors (see below), whose sum is σ = 403560. Its totient is φ = 396256.

The previous prime is 399899. The next prime is 399911. The reversal of 399907 is 709993.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 399907 - 2³ = 399899 is a prime.

It is a Duffinian number.

399907 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (399937) 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, 1657 + ... + 1882.

It is an arithmetic number, because the mean of its divisors is an integer number (100890).

2³⁹⁹⁹⁰⁷ is an apocalyptic number.

399907 is a deficient number, since it is larger than the sum of its proper divisors (3653).

399907 is a wasteful number, since it uses less digits than its factorization.

399907 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3652.

The product of its (nonzero) digits is 15309, while the sum is 37.

The square root of 399907 is about 632.3820048041. The cubic root of 399907 is about 73.6749192814.

The spelling of 399907 in words is "three hundred ninety-nine thousand, nine hundred seven".