989899091 has 2 divisors, whose sum is σ = 989899092. Its totient is φ = 989899090.

The previous prime is 989898997. The next prime is 989899129. The reversal of 989899091 is 190998989.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 989899091 - 2²² = 985704787 is a prime.

It is not a weakly prime, because it can be changed into another prime (989899291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 494949545 + 494949546.

It is an arithmetic number, because the mean of its divisors is an integer number (494949546).

Almost surely, 2^989899091 is an apocalyptic number.

989899091 is a deficient number, since it is larger than the sum of its proper divisors (1).

989899091 is an equidigital number, since it uses as much as digits as its factorization.

989899091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3779136, while the sum is 62.

The square root of 989899091 is about 31462.6618549671. The cubic root of 989899091 is about 996.6216298010.

The spelling of 989899091 in words is "nine hundred eighty-nine million, eight hundred ninety-nine thousand, ninety-one".