91099618 has 4 divisors (see below), whose sum is σ = 136649430. Its totient is φ = 45549808.

The previous prime is 91099609. The next prime is 91099621. The reversal of 91099618 is 81699019.

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

It can be written as a sum of positive squares in only one way, i.e., 89737729 + 1361889 = 9473^2 + 1167^2 .

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 as a sum of consecutive naturals, namely, 22774903 + ... + 22774906.

Almost surely, 2^91099618 is an apocalyptic number.

91099618 is a deficient number, since it is larger than the sum of its proper divisors (45549812).

91099618 is a wasteful number, since it uses less digits than its factorization.

91099618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45549811.

The product of its (nonzero) digits is 34992, while the sum is 43.

The square root of 91099618 is about 9544.6119879228. The cubic root of 91099618 is about 449.9582150502.

The spelling of 91099618 in words is "ninety-one million, ninety-nine thousand, six hundred eighteen".