389991840 has 192 divisors, whose sum is σ = 1442375424. Its totient is φ = 86704128.

The previous prime is 389991839. The next prime is 389991857. The reversal of 389991840 is 48199983.

It is a happy 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, 122752 + ... + 125888.

It is an arithmetic number, because the mean of its divisors is an integer number (7512372).

Almost surely, 2^389991840 is an apocalyptic number.

389991840 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 389991840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (721187712).

389991840 is an abundant number, since it is smaller than the sum of its proper divisors (1052383584).

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

389991840 is a wasteful number, since it uses less digits than its factorization.

389991840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3199 (or 3191 counting only the distinct ones).

The product of its (nonzero) digits is 559872, while the sum is 51.

The square root of 389991840 is about 19748.2110582199. The cubic root of 389991840 is about 730.6092618039.

The spelling of 389991840 in words is "three hundred eighty-nine million, nine hundred ninety-one thousand, eight hundred forty".