9090989 has 2 divisors, whose sum is σ = 9090990. Its totient is φ = 9090988.

The previous prime is 9090973. The next prime is 9091009. The reversal of 9090989 is 9890909.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5442889 + 3648100 = 2333^2 + 1910^2 .

It is a cyclic number.

It is not a de Polignac number, because 9090989 - 2⁴ = 9090973 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9090919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4545494 + 4545495.

It is an arithmetic number, because the mean of its divisors is an integer number (4545495).

Almost surely, 2^9090989 is an apocalyptic number.

It is an amenable number.

9090989 is a deficient number, since it is larger than the sum of its proper divisors (1).

9090989 is an equidigital number, since it uses as much as digits as its factorization.

9090989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 52488, while the sum is 44.

The square root of 9090989 is about 3015.1266971721. The cubic root of 9090989 is about 208.7070137503.

The spelling of 9090989 in words is "nine million, ninety thousand, nine hundred eighty-nine".