90890909 has 2 divisors, whose sum is σ = 90890910. Its totient is φ = 90890908.

The previous prime is 90890897. The next prime is 90890929. The reversal of 90890909 is 90909809.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 86676100 + 4214809 = 9310^2 + 2053^2 .

It is a cyclic number.

It is not a de Polignac number, because 90890909 - 2¹² = 90886813 is a prime.

It is a super-2 number, since 2×90890909² = 16522314677692562, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 90890909.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90890929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45445454 + 45445455.

It is an arithmetic number, because the mean of its divisors is an integer number (45445455).

Almost surely, 2^90890909 is an apocalyptic number.

It is an amenable number.

90890909 is a deficient number, since it is larger than the sum of its proper divisors (1).

90890909 is an equidigital number, since it uses as much as digits as its factorization.

90890909 is an odious number, because the sum of its binary digits is odd.

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

The square root of 90890909 is about 9533.6723774210. The cubic root of 90890909 is about 449.6143345865.

The spelling of 90890909 in words is "ninety million, eight hundred ninety thousand, nine hundred nine".