1981790368 has 48 divisors (see below), whose sum is σ = 4137666624. Its totient is φ = 931138560.

The previous prime is 1981790357. The next prime is 1981790399. The reversal of 1981790368 is 8630971891.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 392983 + ... + 397993.

It is an arithmetic number, because the mean of its divisors is an integer number (86201388).

Almost surely, 2^1981790368 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 1981790368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2068833312).

1981790368 is an abundant number, since it is smaller than the sum of its proper divisors (2155876256).

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

1981790368 is a wasteful number, since it uses less digits than its factorization.

1981790368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5765 (or 5757 counting only the distinct ones).

The product of its (nonzero) digits is 653184, while the sum is 52.

The square root of 1981790368 is about 44517.3041411988. The cubic root of 1981790368 is about 1256.0856027772.

The spelling of 1981790368 in words is "one billion, nine hundred eighty-one million, seven hundred ninety thousand, three hundred sixty-eight".