399657279 has 24 divisors (see below), whose sum is σ = 620780160. Its totient is φ = 228042864.

The previous prime is 399657241. The next prime is 399657283. The reversal of 399657279 is 972756993.

It is not a de Polignac number, because 399657279 - 2⁷ = 399657151 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399657079) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 128262 + ... + 131340.

It is an arithmetic number, because the mean of its divisors is an integer number (25865840).

Almost surely, 2^399657279 is an apocalyptic number.

399657279 is a deficient number, since it is larger than the sum of its proper divisors (221122881).

399657279 is a wasteful number, since it uses less digits than its factorization.

399657279 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3979 (or 3972 counting only the distinct ones).

The product of its digits is 6429780, while the sum is 57.

The square root of 399657279 is about 19991.4301389370. The cubic root of 399657279 is about 736.5958071066.

The spelling of 399657279 in words is "three hundred ninety-nine million, six hundred fifty-seven thousand, two hundred seventy-nine".