91784255856 has 20 divisors (see below), whose sum is σ = 237109327752. Its totient is φ = 30594751936.

The previous prime is 91784255821. The next prime is 91784255863. The reversal of 91784255856 is 65855248719.

It is a self number, because there is not a number n which added to its sum of digits gives 91784255856.

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, 956085951 + ... + 956086046.

Almost surely, 2^91784255856 is an apocalyptic number.

It is an amenable number.

91784255856 is an abundant number, since it is smaller than the sum of its proper divisors (145325071896).

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

91784255856 is a wasteful number, since it uses less digits than its factorization.

91784255856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1912172008 (or 1912172002 counting only the distinct ones).

The product of its digits is 24192000, while the sum is 60.

The spelling of 91784255856 in words is "ninety-one billion, seven hundred eighty-four million, two hundred fifty-five thousand, eight hundred fifty-six".