99921089 has 2 divisors, whose sum is σ = 99921090. Its totient is φ = 99921088.

The previous prime is 99921083. The next prime is 99921109. The reversal of 99921089 is 98012999.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 52200625 + 47720464 = 7225^2 + 6908^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99921089 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (99921083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49960544 + 49960545.

It is an arithmetic number, because the mean of its divisors is an integer number (49960545).

Almost surely, 2^99921089 is an apocalyptic number.

It is an amenable number.

99921089 is a deficient number, since it is larger than the sum of its proper divisors (1).

99921089 is an equidigital number, since it uses as much as digits as its factorization.

99921089 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 104976, while the sum is 47.

The square root of 99921089 is about 9996.0536713245. The cubic root of 99921089 is about 464.0367604274.

The spelling of 99921089 in words is "ninety-nine million, nine hundred twenty-one thousand, eighty-nine".