91015680 has 160 divisors (see below), whose sum is σ = 332728704. Its totient is φ = 20791296.

The previous prime is 91015657. The next prime is 91015697. The reversal of 91015680 is 8651019.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (160).

It is a Harshad number since it is a multiple of its sum of digits (30).

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, 52914 + ... + 54606.

Almost surely, 2^91015680 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 91015680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (166364352).

91015680 is an abundant number, since it is smaller than the sum of its proper divisors (241713024).

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

91015680 is a wasteful number, since it uses less digits than its factorization.

91015680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1726 (or 1710 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 30.

The square root of 91015680 is about 9540.2138340815. The cubic root of 91015680 is about 449.8199773742.

Adding to 91015680 its reverse (8651019), we get a palindrome (99666699).

The spelling of 91015680 in words is "ninety-one million, fifteen thousand, six hundred eighty".