91988106 has 16 divisors (see below), whose sum is σ = 210258624. Its totient is φ = 26282304.

The previous prime is 91988093. The next prime is 91988111. The reversal of 91988106 is 60188919.

It is a Harshad number since it is a multiple of its sum of digits (42), and also a Moran number because the ratio is a prime number: 2190193 = 91988106 / (9 + 1 + 9 + 8 + 8 + 1 + 0 + 6).

It is a Curzon number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 1095055 + ... + 1095138.

It is an arithmetic number, because the mean of its divisors is an integer number (13141164).

Almost surely, 2^91988106 is an apocalyptic number.

91988106 is an abundant number, since it is smaller than the sum of its proper divisors (118270518).

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

91988106 is a wasteful number, since it uses less digits than its factorization.

91988106 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2190205.

The product of its (nonzero) digits is 31104, while the sum is 42.

The square root of 91988106 is about 9591.0430089746. The cubic root of 91988106 is about 451.4162884454.

The spelling of 91988106 in words is "ninety-one million, nine hundred eighty-eight thousand, one hundred six".