91109201020 has 24 divisors (see below), whose sum is σ = 193117451184. Its totient is φ = 36103084416.

The previous prime is 91109201009. The next prime is 91109201021. The reversal of 91109201020 is 2010290119.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91109201021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21285057 + ... + 21289336.

It is an arithmetic number, because the mean of its divisors is an integer number (8046560466).

Almost surely, 2^91109201020 is an apocalyptic number.

It is an amenable number.

91109201020 is an abundant number, since it is smaller than the sum of its proper divisors (102008250164).

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

91109201020 is a wasteful number, since it uses less digits than its factorization.

91109201020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42574509 (or 42574507 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 25.

Adding to 91109201020 its reverse (2010290119), we get a palindrome (93119491139).

The spelling of 91109201020 in words is "ninety-one billion, one hundred nine million, two hundred one thousand, twenty".