91221100 has 18 divisors (see below), whose sum is σ = 197950004. Its totient is φ = 36488400.

The previous prime is 91221089. The next prime is 91221101. The reversal of 91221100 is 112219.

It is not an unprimeable number, because it can be changed into a prime (91221101) 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 5 ways as a sum of consecutive naturals, for example, 456006 + ... + 456205.

Almost surely, 2^91221100 is an apocalyptic number.

It is an amenable number.

91221100 is an abundant number, since it is smaller than the sum of its proper divisors (106728904).

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

91221100 is a wasteful number, since it uses less digits than its factorization.

91221100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 912225 (or 912218 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 16.

The square root of 91221100 is about 9550.9737723438. The cubic root of 91221100 is about 450.1581337244.

Adding to 91221100 its reverse (112219), we get a palindrome (91333319).

The spelling of 91221100 in words is "ninety-one million, two hundred twenty-one thousand, one hundred".