91820111 has 16 divisors (see below), whose sum is σ = 99532800. Its totient is φ = 84389760.

The previous prime is 91820087. The next prime is 91820123. The reversal of 91820111 is 11102819.

It is a cyclic number.

It is not a de Polignac number, because 91820111 - 2¹⁰ = 91819087 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91820411) 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 15 ways as a sum of consecutive naturals, for example, 152990 + ... + 153588.

It is an arithmetic number, because the mean of its divisors is an integer number (6220800).

Almost surely, 2^91820111 is an apocalyptic number.

91820111 is a deficient number, since it is larger than the sum of its proper divisors (7712689).

91820111 is a wasteful number, since it uses less digits than its factorization.

91820111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 814.

The product of its (nonzero) digits is 144, while the sum is 23.

The square root of 91820111 is about 9582.2810958560. The cubic root of 91820111 is about 451.1413185063.

The spelling of 91820111 in words is "ninety-one million, eight hundred twenty thousand, one hundred eleven".