90031309 has 2 divisors, whose sum is σ = 90031310. Its totient is φ = 90031308.

The previous prime is 90031307. The next prime is 90031321. The reversal of 90031309 is 90313009.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 84695209 + 5336100 = 9203^2 + 2310^2 .

It is a cyclic number.

It is not a de Polignac number, because 90031309 - 2¹ = 90031307 is a prime.

Together with 90031307, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90031301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45015654 + 45015655.

It is an arithmetic number, because the mean of its divisors is an integer number (45015655).

Almost surely, 2^90031309 is an apocalyptic number.

It is an amenable number.

90031309 is a deficient number, since it is larger than the sum of its proper divisors (1).

90031309 is an equidigital number, since it uses as much as digits as its factorization.

90031309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 729, while the sum is 25.

The square root of 90031309 is about 9488.4829662070. The cubic root of 90031309 is about 448.1924346684.

The spelling of 90031309 in words is "ninety million, thirty-one thousand, three hundred nine".