91117011220 has 24 divisors (see below), whose sum is σ = 191361588264. Its totient is φ = 36443782656.

The previous prime is 91117011203. The next prime is 91117011221. The reversal of 91117011220 is 2211071119.

It can be written as a sum of positive squares in 4 ways, for example, as 45230230276 + 45886780944 = 212674^2 + 214212^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91117011221) 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, 66832 + ... + 432088.

It is an arithmetic number, because the mean of its divisors is an integer number (7973399511).

Almost surely, 2^91117011220 is an apocalyptic number.

It is an amenable number.

91117011220 is an abundant number, since it is smaller than the sum of its proper divisors (100244577044).

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

91117011220 is a wasteful number, since it uses less digits than its factorization.

91117011220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 377739 (or 377737 counting only the distinct ones).

The product of its (nonzero) digits is 252, while the sum is 25.

Adding to 91117011220 its reverse (2211071119), we get a palindrome (93328082339).

The spelling of 91117011220 in words is "ninety-one billion, one hundred seventeen million, eleven thousand, two hundred twenty".