91680881 has 8 divisors (see below), whose sum is σ = 97966440. Its totient is φ = 85494528.

The previous prime is 91680877. The next prime is 91680889. The reversal of 91680881 is 18808619.

It can be written as a sum of positive squares in 4 ways, for example, as 20784481 + 70896400 = 4559^2 + 8420^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 91680881 - 2² = 91680877 is a prime.

It is a super-2 number, since 2×91680881² = 16810767881872322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91680889) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22886 + ... + 26591.

It is an arithmetic number, because the mean of its divisors is an integer number (12245805).

Almost surely, 2^91680881 is an apocalyptic number.

It is an amenable number.

91680881 is a deficient number, since it is larger than the sum of its proper divisors (6285559).

91680881 is a wasteful number, since it uses less digits than its factorization.

91680881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49603.

The product of its (nonzero) digits is 27648, while the sum is 41.

The square root of 91680881 is about 9575.0133681369. The cubic root of 91680881 is about 450.9131761090.

The spelling of 91680881 in words is "ninety-one million, six hundred eighty thousand, eight hundred eighty-one".