1991983360 has 72 divisors (see below), whose sum is σ = 4887927576. Its totient is φ = 777338880.

The previous prime is 1991983327. The next prime is 1991983387. The reversal of 1991983360 is 633891991.

It can be written as a sum of positive squares in 4 ways, for example, as 164249856 + 1827733504 = 12816^2 + 42752^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33502 + ... + 71458.

It is an arithmetic number, because the mean of its divisors is an integer number (67887883).

Almost surely, 2^1991983360 is an apocalyptic number.

1991983360 is a gapful number since it is divisible by the number (10) 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 1991983360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2443963788).

1991983360 is an abundant number, since it is smaller than the sum of its proper divisors (2895944216).

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

1991983360 is an equidigital number, since it uses as much as digits as its factorization.

1991983360 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38019 (or 38005 counting only the distinct ones).

The product of its (nonzero) digits is 314928, while the sum is 49.

The square root of 1991983360 is about 44631.6407943961. The cubic root of 1991983360 is about 1258.2354067715.

The spelling of 1991983360 in words is "one billion, nine hundred ninety-one million, nine hundred eighty-three thousand, three hundred sixty".