393987840 has 288 divisors, whose sum is σ = 1342172160. Its totient is φ = 98353152.

The previous prime is 393987833. The next prime is 393987863. The reversal of 393987840 is 48789393.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6677731 + ... + 6677789.

It is an arithmetic number, because the mean of its divisors is an integer number (4660320).

Almost surely, 2^393987840 is an apocalyptic number.

393987840 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 393987840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (671086080).

393987840 is an abundant number, since it is smaller than the sum of its proper divisors (948184320).

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

393987840 is a wasteful number, since it uses less digits than its factorization.

393987840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167 (or 153 counting only the distinct ones).

The product of its (nonzero) digits is 1306368, while the sum is 51.

The square root of 393987840 is about 19849.1269329409. The cubic root of 393987840 is about 733.0961510282.

The spelling of 393987840 in words is "three hundred ninety-three million, nine hundred eighty-seven thousand, eight hundred forty".