399293440 has 176 divisors, whose sum is σ = 1180251072. Its totient is φ = 126222336.

The previous prime is 399293437. The next prime is 399293441. The reversal of 399293440 is 44392993.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399293441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 465492 + ... + 466348.

It is an arithmetic number, because the mean of its divisors is an integer number (6705972).

Almost surely, 2^399293440 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 399293440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (590125536).

399293440 is an abundant number, since it is smaller than the sum of its proper divisors (780957632).

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

399293440 is a wasteful number, since it uses less digits than its factorization.

399293440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 902 (or 884 counting only the distinct ones).

The product of its (nonzero) digits is 209952, while the sum is 43.

The square root of 399293440 is about 19982.3281926807. The cubic root of 399293440 is about 736.3722124878.

The spelling of 399293440 in words is "three hundred ninety-nine million, two hundred ninety-three thousand, four hundred forty".