399669879 has 16 divisors (see below), whose sum is σ = 609493248. Its totient is φ = 228205632.

The previous prime is 399669869. The next prime is 399669913. The reversal of 399669879 is 978966993.

It is not a de Polignac number, because 399669879 - 2²³ = 391281271 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399669839) 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 15 ways as a sum of consecutive naturals, for example, 23299 + ... + 36635.

It is an arithmetic number, because the mean of its divisors is an integer number (38093328).

Almost surely, 2^399669879 is an apocalyptic number.

399669879 is a deficient number, since it is larger than the sum of its proper divisors (209823369).

399669879 is a wasteful number, since it uses less digits than its factorization.

399669879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14774.

The product of its digits is 39680928, while the sum is 66.

The square root of 399669879 is about 19991.7452714864. The cubic root of 399669879 is about 736.6035479136.

The spelling of 399669879 in words is "three hundred ninety-nine million, six hundred sixty-nine thousand, eight hundred seventy-nine".