399847680 has 216 divisors, whose sum is σ = 1408581720. Its totient is φ = 104693760.

The previous prime is 399847649. The next prime is 399847699. The reversal of 399847680 is 86748993.

399847680 is a `hidden beast` number, since 3 + 9 + 98 + 476 + 80 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 10653696 + 389193984 = 3264^2 + 19728^2 .

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 702436 + ... + 703004.

Almost surely, 2^399847680 is an apocalyptic number.

399847680 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 399847680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (704290860).

399847680 is an abundant number, since it is smaller than the sum of its proper divisors (1008734040).

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

399847680 is a wasteful number, since it uses less digits than its factorization.

399847680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 657 (or 640 counting only the distinct ones).

The product of its (nonzero) digits is 2612736, while the sum is 54.

The square root of 399847680 is about 19996.1916374094. The cubic root of 399847680 is about 736.7127625744.

The spelling of 399847680 in words is "three hundred ninety-nine million, eight hundred forty-seven thousand, six hundred eighty".