399320940 has 96 divisors (see below), whose sum is σ = 1171054080. Its totient is φ = 101669568.

The previous prime is 399320903. The next prime is 399320941. The reversal of 399320940 is 49023993.

It is not an unprimeable number, because it can be changed into a prime (399320941) 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 31 ways as a sum of consecutive naturals, for example, 729747 + ... + 730293.

It is an arithmetic number, because the mean of its divisors is an integer number (12198480).

Almost surely, 2^399320940 is an apocalyptic number.

399320940 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 399320940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (585527040).

399320940 is an abundant number, since it is smaller than the sum of its proper divisors (771733140).

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

399320940 is a wasteful number, since it uses less digits than its factorization.

399320940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 628 (or 580 counting only the distinct ones).

The product of its (nonzero) digits is 52488, while the sum is 39.

The square root of 399320940 is about 19983.0162888389. The cubic root of 399320940 is about 736.3891171574.

The spelling of 399320940 in words is "three hundred ninety-nine million, three hundred twenty thousand, nine hundred forty".