1991930380836 has 96 divisors (see below), whose sum is σ = 5291409328128. Its totient is φ = 577306709760.

The previous prime is 1991930380829. The next prime is 1991930380849. The reversal of 1991930380836 is 6380830391991.

It is a self number, because there is not a number n which added to its sum of digits gives 1991930380836.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 31716081 + ... + 31778823.

It is an arithmetic number, because the mean of its divisors is an integer number (55118847168).

Almost surely, 2^{1991930380836} is an apocalyptic number.

It is an amenable number.

1991930380836 is an abundant number, since it is smaller than the sum of its proper divisors (3299478947292).

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

1991930380836 is a wasteful number, since it uses less digits than its factorization.

1991930380836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73241 (or 73239 counting only the distinct ones).

The product of its (nonzero) digits is 7558272, while the sum is 60.

The spelling of 1991930380836 in words is "one trillion, nine hundred ninety-one billion, nine hundred thirty million, three hundred eighty thousand, eight hundred thirty-six".