399856988 has 12 divisors (see below), whose sum is σ = 723879240. Its totient is φ = 193034352.

The previous prime is 399856987. The next prime is 399857011. The reversal of 399856988 is 889658993.

It is a super-2 number, since 2×399856988² = 319771221704864288, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399856987) 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 3 ways as a sum of consecutive naturals, for example, 1723406 + ... + 1723637.

It is an arithmetic number, because the mean of its divisors is an integer number (60323270).

Almost surely, 2^399856988 is an apocalyptic number.

It is an amenable number.

399856988 is a deficient number, since it is larger than the sum of its proper divisors (324022252).

399856988 is a wasteful number, since it uses less digits than its factorization.

399856988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3447076 (or 3447074 counting only the distinct ones).

The product of its digits is 33592320, while the sum is 65.

The square root of 399856988 is about 19996.4243803736. The cubic root of 399856988 is about 736.7184791423.

The spelling of 399856988 in words is "three hundred ninety-nine million, eight hundred fifty-six thousand, nine hundred eighty-eight".