1991442320 has 60 divisors (see below), whose sum is σ = 5386049244. Its totient is φ = 682778880.

The previous prime is 1991442319. The next prime is 1991442331. The reversal of 1991442320 is 232441991.

It can be written as a sum of positive squares in 2 ways, for example, as 1475789056 + 515653264 = 38416^2 + 22708^2 .

It is a Harshad number since it is a multiple of its sum of digits (35).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 250091 + ... + 257930.

Almost surely, 2^1991442320 is an apocalyptic number.

1991442320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1991442320 is an abundant number, since it is smaller than the sum of its proper divisors (3394606924).

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

1991442320 is a wasteful number, since it uses less digits than its factorization.

1991442320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 508048 (or 508035 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 35.

The square root of 1991442320 is about 44625.5792119273. The cubic root of 1991442320 is about 1258.1214805643.

The spelling of 1991442320 in words is "one billion, nine hundred ninety-one million, four hundred forty-two thousand, three hundred twenty".