1018991680 has 56 divisors (see below), whose sum is σ = 2773119168. Its totient is φ = 349367808.

The previous prime is 1018991629. The next prime is 1018991711. The reversal of 1018991680 is 861998101.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (56).

It is a hoax number, since the sum of its digits (43) coincides with the sum of the digits of its distinct prime factors.

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, 225214 + ... + 229693.

Almost surely, 2^1018991680 is an apocalyptic number.

1018991680 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1018991680 is an abundant number, since it is smaller than the sum of its proper divisors (1754127488).

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

1018991680 is an equidigital number, since it uses as much as digits as its factorization.

1018991680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 454931 (or 454921 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 43.

The square root of 1018991680 is about 31921.6490802089. The cubic root of 1018991680 is about 1006.2909015690.

The spelling of 1018991680 in words is "one billion, eighteen million, nine hundred ninety-one thousand, six hundred eighty".