18922909 has 2 divisors, whose sum is σ = 18922910. Its totient is φ = 18922908.

The previous prime is 18922907. The next prime is 18922931. The reversal of 18922909 is 90922981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15132100 + 3790809 = 3890^2 + 1947^2 .

It is a cyclic number.

It is not a de Polignac number, because 18922909 - 2¹ = 18922907 is a prime.

Together with 18922907, 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 (18922901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9461454 + 9461455.

It is an arithmetic number, because the mean of its divisors is an integer number (9461455).

Almost surely, 2^18922909 is an apocalyptic number.

It is an amenable number.

18922909 is a deficient number, since it is larger than the sum of its proper divisors (1).

18922909 is an equidigital number, since it uses as much as digits as its factorization.

18922909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23328, while the sum is 40.

The square root of 18922909 is about 4350.0470112402. The cubic root of 18922909 is about 266.4787813680.

The spelling of 18922909 in words is "eighteen million, nine hundred twenty-two thousand, nine hundred nine".