91770971568 has 80 divisors (see below), whose sum is σ = 241080105600. Its totient is φ = 30077386240.

The previous prime is 91770971549. The next prime is 91770971587. The reversal of 91770971568 is 86517907719.

It is an interprime number because it is at equal distance from previous prime (91770971549) and next prime (91770971587).

It is a super-2 number, since 2×91770971568² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 704683 + ... + 824693.

It is an arithmetic number, because the mean of its divisors is an integer number (3013501320).

Almost surely, 2^91770971568 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 91770971568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120540052800).

91770971568 is an abundant number, since it is smaller than the sum of its proper divisors (149309134032).

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

91770971568 is a wasteful number, since it uses less digits than its factorization.

91770971568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120290 (or 120284 counting only the distinct ones).

The product of its (nonzero) digits is 6667920, while the sum is 60.

The spelling of 91770971568 in words is "ninety-one billion, seven hundred seventy million, nine hundred seventy-one thousand, five hundred sixty-eight".