20312309 has 2 divisors, whose sum is σ = 20312310. Its totient is φ = 20312308.

The previous prime is 20312293. The next prime is 20312351. The reversal of 20312309 is 90321302.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13140625 + 7171684 = 3625^2 + 2678^2 .

It is a cyclic number.

It is not a de Polignac number, because 20312309 - 2⁴ = 20312293 is a prime.

It is a super-2 number, since 2×20312309² = 825179793822962, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20312359) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10156154 + 10156155.

It is an arithmetic number, because the mean of its divisors is an integer number (10156155).

Almost surely, 2^20312309 is an apocalyptic number.

It is an amenable number.

20312309 is a deficient number, since it is larger than the sum of its proper divisors (1).

20312309 is an equidigital number, since it uses as much as digits as its factorization.

20312309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 324, while the sum is 20.

The square root of 20312309 is about 4506.9179047327. The cubic root of 20312309 is about 272.8473655583.

The spelling of 20312309 in words is "twenty million, three hundred twelve thousand, three hundred nine".