91099100920 has 16 divisors (see below), whose sum is σ = 204972977160. Its totient is φ = 36439640352.

The previous prime is 91099100887. The next prime is 91099100927. The reversal of 91099100920 is 2900199019.

It is a Harshad number since it is a multiple of its sum of digits (40), and also a Moran number because the ratio is a prime number: 2277477523 = 91099100920 / (9 + 1 + 0 + 9 + 9 + 1 + 0 + 0 + 9 + 2 + 0).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91099100927) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1138738722 + ... + 1138738801.

Almost surely, 2^91099100920 is an apocalyptic number.

It is an amenable number.

91099100920 is an abundant number, since it is smaller than the sum of its proper divisors (113873876240).

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

91099100920 is a wasteful number, since it uses less digits than its factorization.

91099100920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2277477534 (or 2277477530 counting only the distinct ones).

The product of its (nonzero) digits is 13122, while the sum is 40.

Adding to 91099100920 its reverse (2900199019), we get a palindrome (93999299939).

The spelling of 91099100920 in words is "ninety-one billion, ninety-nine million, one hundred thousand, nine hundred twenty".