91220111 has 4 divisors (see below), whose sum is σ = 91455000. Its totient is φ = 90985224.

The previous prime is 91220057. The next prime is 91220117. The reversal of 91220111 is 11102219.

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-91220111 is a prime.

It is a super-2 number, since 2×91220111² = 16642217301704642, which contains 22 as substring.

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 91220111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91220117) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 116861 + ... + 117638.

It is an arithmetic number, because the mean of its divisors is an integer number (22863750).

Almost surely, 2^91220111 is an apocalyptic number.

91220111 is a deficient number, since it is larger than the sum of its proper divisors (234889).

91220111 is a wasteful number, since it uses less digits than its factorization.

91220111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234888.

The product of its (nonzero) digits is 36, while the sum is 17.

The square root of 91220111 is about 9550.9219973781. The cubic root of 91220111 is about 450.1565068786.

The spelling of 91220111 in words is "ninety-one million, two hundred twenty thousand, one hundred eleven".