399687 has 12 divisors (see below), whose sum is σ = 567336. Its totient is φ = 250240.

The previous prime is 399677. The next prime is 399689. The reversal of 399687 is 786993.

It is a happy number.

It is not a de Polignac number, because 399687 - 2¹⁴ = 383303 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399689) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 637 + ... + 1097.

It is an arithmetic number, because the mean of its divisors is an integer number (47278).

2³⁹⁹⁶⁸⁷ is an apocalyptic number.

399687 is a deficient number, since it is larger than the sum of its proper divisors (167649).

399687 is a wasteful number, since it uses less digits than its factorization.

399687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 498 (or 481 counting only the distinct ones).

The product of its digits is 81648, while the sum is 42.

The square root of 399687 is about 632.2080353808. The cubic root of 399687 is about 73.6614065935.

The spelling of 399687 in words is "three hundred ninety-nine thousand, six hundred eighty-seven".