399759840 has 384 divisors, whose sum is σ = 1496154240. Its totient is φ = 99532800.

The previous prime is 399759823. The next prime is 399759859. The reversal of 399759840 is 48957993.

399759840 is a `hidden beast` number, since 3 + 9 + 9 + 7 + 598 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

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 63 ways as a sum of consecutive naturals, for example, 6553410 + ... + 6553470.

It is an arithmetic number, because the mean of its divisors is an integer number (3896235).

Almost surely, 2^399759840 is an apocalyptic number.

399759840 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 399759840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (748077120).

399759840 is an abundant number, since it is smaller than the sum of its proper divisors (1096394400).

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

399759840 is a wasteful number, since it uses less digits than its factorization.

399759840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163 (or 149 counting only the distinct ones).

The product of its (nonzero) digits is 2449440, while the sum is 54.

The square root of 399759840 is about 19993.9950985290. The cubic root of 399759840 is about 736.6588107059.

The spelling of 399759840 in words is "three hundred ninety-nine million, seven hundred fifty-nine thousand, eight hundred forty".