991274617800 has 144 divisors (see below), whose sum is σ = 3329540662500. Its totient is φ = 264299397120.

The previous prime is 991274617789. The next prime is 991274617843. The reversal of 991274617800 is 8716472199.

991274617800 is a `hidden beast` number, since 9 + 9 + 12 + 7 + 4 + 617 + 8 + 0 + 0 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 107648297604 + 883626320196 = 328098^2 + 940014^2 .

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 35 ways as a sum of consecutive naturals, for example, 12793576 + ... + 12870824.

Almost surely, 2^991274617800 is an apocalyptic number.

991274617800 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

991274617800 is an abundant number, since it is smaller than the sum of its proper divisors (2338266044700).

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

991274617800 is a wasteful number, since it uses less digits than its factorization.

991274617800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84400 (or 84388 counting only the distinct ones).

The product of its (nonzero) digits is 1524096, while the sum is 54.

The spelling of 991274617800 in words is "nine hundred ninety-one billion, two hundred seventy-four million, six hundred seventeen thousand, eight hundred".