91004773840 has 20 divisors (see below), whose sum is σ = 211586099364. Its totient is φ = 36401909504.

The previous prime is 91004773807. The next prime is 91004773891. The reversal of 91004773840 is 4837740019.

It can be written as a sum of positive squares in 2 ways, for example, as 61577429904 + 29427343936 = 248148^2 + 171544^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 568779757 + ... + 568779916.

Almost surely, 2^91004773840 is an apocalyptic number.

It is an amenable number.

91004773840 is an abundant number, since it is smaller than the sum of its proper divisors (120581325524).

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

91004773840 is a wasteful number, since it uses less digits than its factorization.

91004773840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1137559686 (or 1137559680 counting only the distinct ones).

The product of its (nonzero) digits is 169344, while the sum is 43.

The spelling of 91004773840 in words is "ninety-one billion, four million, seven hundred seventy-three thousand, eight hundred forty".