91222091 has 4 divisors (see below), whose sum is σ = 91335384. Its totient is φ = 91108800.

The previous prime is 91222069. The next prime is 91222093. The reversal of 91222091 is 19022219.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91222091 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 91222091.

It is not an unprimeable number, because it can be changed into a prime (91222093) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55430 + ... + 57051.

It is an arithmetic number, because the mean of its divisors is an integer number (22833846).

Almost surely, 2^91222091 is an apocalyptic number.

91222091 is a deficient number, since it is larger than the sum of its proper divisors (113293).

91222091 is a wasteful number, since it uses less digits than its factorization.

91222091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113292.

The product of its (nonzero) digits is 648, while the sum is 26.

The square root of 91222091 is about 9551.0256517298. The cubic root of 91222091 is about 450.1597638483.

The spelling of 91222091 in words is "ninety-one million, two hundred twenty-two thousand, ninety-one".