91840881 has 16 divisors (see below), whose sum is σ = 133898688. Its totient is φ = 55531200.

The previous prime is 91840871. The next prime is 91840907. The reversal of 91840881 is 18804819.

It is a happy number.

It is not a de Polignac number, because 91840881 - 2⁵ = 91840849 is a prime.

It is a super-2 number, since 2×91840881² = 16869494845712322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (91840871) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12195 + ... + 18231.

It is an arithmetic number, because the mean of its divisors is an integer number (8368668).

Almost surely, 2^91840881 is an apocalyptic number.

It is an amenable number.

91840881 is a deficient number, since it is larger than the sum of its proper divisors (42057807).

91840881 is a wasteful number, since it uses less digits than its factorization.

91840881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6512.

The product of its (nonzero) digits is 18432, while the sum is 39.

The square root of 91840881 is about 9583.3648057454. The cubic root of 91840881 is about 451.1753324736.

The spelling of 91840881 in words is "ninety-one million, eight hundred forty thousand, eight hundred eighty-one".