99090090221 has 2 divisors, whose sum is σ = 99090090222. Its totient is φ = 99090090220.

The previous prime is 99090090173. The next prime is 99090090223. The reversal of 99090090221 is 12209009099.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59628267721 + 39461822500 = 244189^2 + 198650^2 .

It is a cyclic number.

It is not a de Polignac number, because 99090090221 - 2³⁴ = 81910221037 is a prime.

Together with 99090090223, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99090090223) 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 as a sum of consecutive naturals, namely, 49545045110 + 49545045111.

It is an arithmetic number, because the mean of its divisors is an integer number (49545045111).

Almost surely, 2^99090090221 is an apocalyptic number.

It is an amenable number.

99090090221 is a deficient number, since it is larger than the sum of its proper divisors (1).

99090090221 is an equidigital number, since it uses as much as digits as its factorization.

99090090221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 26244, while the sum is 41.

The spelling of 99090090221 in words is "ninety-nine billion, ninety million, ninety thousand, two hundred twenty-one".