91216501280 has 48 divisors (see below), whose sum is σ = 219031777944. Its totient is φ = 35888455680.

The previous prime is 91216501241. The next prime is 91216501309. The reversal of 91216501280 is 8210561219.

It can be written as a sum of positive squares in 4 ways, for example, as 50536838416 + 40679662864 = 224804^2 + 201692^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 91216501280.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4663217 + ... + 4682736.

Almost surely, 2^91216501280 is an apocalyptic number.

It is an amenable number.

91216501280 is an abundant number, since it is smaller than the sum of its proper divisors (127815276664).

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

91216501280 is a wasteful number, since it uses less digits than its factorization.

91216501280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9346029 (or 9346021 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 35.

The spelling of 91216501280 in words is "ninety-one billion, two hundred sixteen million, five hundred one thousand, two hundred eighty".