91995221 has 16 divisors (see below), whose sum is σ = 97675200. Its totient is φ = 86515968.

The previous prime is 91995217. The next prime is 91995223. The reversal of 91995221 is 12259919.

It is a cyclic number.

It is not a de Polignac number, because 91995221 - 2² = 91995217 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 (91995223) 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 15 ways as a sum of consecutive naturals, for example, 219350 + ... + 219768.

It is an arithmetic number, because the mean of its divisors is an integer number (6104700).

Almost surely, 2^91995221 is an apocalyptic number.

It is an amenable number.

91995221 is a deficient number, since it is larger than the sum of its proper divisors (5679979).

91995221 is a wasteful number, since it uses less digits than its factorization.

91995221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 628.

The product of its digits is 14580, while the sum is 38.

The square root of 91995221 is about 9591.4139207940. The cubic root of 91995221 is about 451.4279267040.

The spelling of 91995221 in words is "ninety-one million, nine hundred ninety-five thousand, two hundred twenty-one".