20662309 has 2 divisors, whose sum is σ = 20662310. Its totient is φ = 20662308.

The previous prime is 20662307. The next prime is 20662333. The reversal of 20662309 is 90326602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15233409 + 5428900 = 3903^2 + 2330^2 .

It is a cyclic number.

It is not a de Polignac number, because 20662309 - 2¹ = 20662307 is a prime.

It is a super-2 number, since 2×20662309² = 853862026422962, which contains 22 as substring.

Together with 20662307, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20662307) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10331154 + 10331155.

It is an arithmetic number, because the mean of its divisors is an integer number (10331155).

Almost surely, 2^20662309 is an apocalyptic number.

It is an amenable number.

20662309 is a deficient number, since it is larger than the sum of its proper divisors (1).

20662309 is an equidigital number, since it uses as much as digits as its factorization.

20662309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 28.

The square root of 20662309 is about 4545.5812609610. The cubic root of 20662309 is about 274.4055877294.

The spelling of 20662309 in words is "twenty million, six hundred sixty-two thousand, three hundred nine".