91881659 has 4 divisors (see below), whose sum is σ = 92724720. Its totient is φ = 91038600.

The previous prime is 91881637. The next prime is 91881667. The reversal of 91881659 is 95618819.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 91881659 - 2⁸ = 91881403 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91881679) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 421367 + ... + 421584.

It is an arithmetic number, because the mean of its divisors is an integer number (23181180).

Almost surely, 2^91881659 is an apocalyptic number.

91881659 is a deficient number, since it is larger than the sum of its proper divisors (843061).

91881659 is a wasteful number, since it uses less digits than its factorization.

91881659 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 843060.

The product of its digits is 155520, while the sum is 47.

The square root of 91881659 is about 9585.4921104761. The cubic root of 91881659 is about 451.2420976049.

The spelling of 91881659 in words is "ninety-one million, eight hundred eighty-one thousand, six hundred fifty-nine".