91019390920 has 16 divisors (see below), whose sum is σ = 204793629660. Its totient is φ = 36407756352.

The previous prime is 91019390909. The next prime is 91019390939. The reversal of 91019390920 is 2909391019.

It can be written as a sum of positive squares in 2 ways, for example, as 81989450244 + 9029940676 = 286338^2 + 95026^2 .

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 3 ways as a sum of consecutive naturals, for example, 1137742347 + ... + 1137742426.

Almost surely, 2^91019390920 is an apocalyptic number.

It is an amenable number.

91019390920 is an abundant number, since it is smaller than the sum of its proper divisors (113774238740).

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

91019390920 is a wasteful number, since it uses less digits than its factorization.

91019390920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2275484784 (or 2275484780 counting only the distinct ones).

The product of its (nonzero) digits is 39366, while the sum is 43.

The spelling of 91019390920 in words is "ninety-one billion, nineteen million, three hundred ninety thousand, nine hundred twenty".