91156220 has 24 divisors (see below), whose sum is σ = 192344208. Its totient is φ = 36288000.

The previous prime is 91156147. The next prime is 91156229. The reversal of 91156220 is 2265119.

91156220 is digitally balanced in base 9, because in such base it contains all the possibile digits an equal number of times.

91156220 is strictly pandigital in base 9.

It is a self number, because there is not a number n which added to its sum of digits gives 91156220.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91156229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6581 + ... + 15020.

It is an arithmetic number, because the mean of its divisors is an integer number (8014342).

Almost surely, 2^91156220 is an apocalyptic number.

It is an amenable number.

91156220 is an abundant number, since it is smaller than the sum of its proper divisors (101187988).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

91156220 is a wasteful number, since it uses less digits than its factorization.

91156220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21821 (or 21819 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 91156220 is about 9547.5766558850. The cubic root of 91156220 is about 450.0513850787.

The spelling of 91156220 in words is "ninety-one million, one hundred fifty-six thousand, two hundred twenty".