90090919091 has 4 divisors (see below), whose sum is σ = 90181829184. Its totient is φ = 90000009000.

The previous prime is 90090919073. The next prime is 90090919097. The reversal of 90090919091 is 19091909009.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-90090919091 is a prime.

It is a super-2 number, since 2×90090919091² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (90090919097) 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, 45453560 + ... + 45455541.

It is an arithmetic number, because the mean of its divisors is an integer number (22545457296).

Almost surely, 2^90090919091 is an apocalyptic number.

90090919091 is a deficient number, since it is larger than the sum of its proper divisors (90910093).

90090919091 is an equidigital number, since it uses as much as digits as its factorization.

90090919091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90910092.

The product of its (nonzero) digits is 59049, while the sum is 47.

The spelling of 90090919091 in words is "ninety billion, ninety million, nine hundred nineteen thousand, ninety-one".