399676840 has 72 divisors (see below), whose sum is σ = 939974490. Its totient is φ = 152941824.

The previous prime is 399676829. The next prime is 399676841. The reversal of 399676840 is 48676993.

It can be written as a sum of positive squares in 9 ways, for example, as 108701476 + 290975364 = 10426^2 + 17058^2 .

It is not an unprimeable number, because it can be changed into a prime (399676841) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 3666706 + ... + 3666814.

Almost surely, 2^399676840 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 399676840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (469987245).

399676840 is an abundant number, since it is smaller than the sum of its proper divisors (540297650).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

399676840 is a wasteful number, since it uses less digits than its factorization.

399676840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 287 (or 145 counting only the distinct ones).

The product of its (nonzero) digits is 1959552, while the sum is 52.

The square root of 399676840 is about 19991.9193675845. The cubic root of 399676840 is about 736.6078243325.

The spelling of 399676840 in words is "three hundred ninety-nine million, six hundred seventy-six thousand, eight hundred forty".