91281384568 has 24 divisors (see below), whose sum is σ = 188126409240. Its totient is φ = 41491538000.

The previous prime is 91281384563. The next prime is 91281384659. The reversal of 91281384568 is 86548318219.

It is a happy number.

It is a super-2 number, since 2×91281384568² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91281384563) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 47148508 + ... + 47150443.

It is an arithmetic number, because the mean of its divisors is an integer number (7838600385).

Almost surely, 2^91281384568 is an apocalyptic number.

It is an amenable number.

91281384568 is an abundant number, since it is smaller than the sum of its proper divisors (96845024672).

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

91281384568 is a wasteful number, since it uses less digits than its factorization.

91281384568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94298979 (or 94298964 counting only the distinct ones).

The product of its digits is 3317760, while the sum is 55.

The spelling of 91281384568 in words is "ninety-one billion, two hundred eighty-one million, three hundred eighty-four thousand, five hundred sixty-eight".