91939778560 has 208 divisors, whose sum is σ = 258976616256. Its totient is φ = 30668488704.

The previous prime is 91939778519. The next prime is 91939778587. The reversal of 91939778560 is 6587793919.

It is a Harshad number since it is a multiple of its sum of digits (64).

It is a junction number, because it is equal to n+sod(n) for n = 91939778492 and 91939778501.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5295654 + ... + 5312986.

Almost surely, 2^91939778560 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91939778560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (129488308128).

91939778560 is an abundant number, since it is smaller than the sum of its proper divisors (167036837696).

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

91939778560 is a wasteful number, since it uses less digits than its factorization.

91939778560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17406 (or 17384 counting only the distinct ones).

The product of its (nonzero) digits is 25719120, while the sum is 64.

The spelling of 91939778560 in words is "ninety-one billion, nine hundred thirty-nine million, seven hundred seventy-eight thousand, five hundred sixty".