91281572928 has 672 divisors, whose sum is σ = 341776547840. Its totient is φ = 22618828800.

The previous prime is 91281572917. The next prime is 91281572953. The reversal of 91281572928 is 82927518219.

It is a tau number, because it is divible by the number of its divisors (672).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 150381201 + ... + 150381807.

Almost surely, 2^91281572928 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 91281572928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (170888273920).

91281572928 is an abundant number, since it is smaller than the sum of its proper divisors (250494974912).

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

91281572928 is a wasteful number, since it uses less digits than its factorization.

91281572928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 815 (or 802 counting only the distinct ones).

The product of its digits is 1451520, while the sum is 54.

The spelling of 91281572928 in words is "ninety-one billion, two hundred eighty-one million, five hundred seventy-two thousand, nine hundred twenty-eight".