91800885990 has 32 divisors (see below), whose sum is σ = 240351411456. Its totient is φ = 22254760160.

The previous prime is 91800885971. The next prime is 91800886007. The reversal of 91800885990 is 9958800819.

It is a self number, because there is not a number n which added to its sum of digits gives 91800885990.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 139091922 + ... + 139092581.

It is an arithmetic number, because the mean of its divisors is an integer number (7510981608).

Almost surely, 2^91800885990 is an apocalyptic number.

91800885990 is an abundant number, since it is smaller than the sum of its proper divisors (148550525466).

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

91800885990 is a wasteful number, since it uses less digits than its factorization.

91800885990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 278184524.

The product of its (nonzero) digits is 1866240, while the sum is 57.

The spelling of 91800885990 in words is "ninety-one billion, eight hundred million, eight hundred eighty-five thousand, nine hundred ninety".