18919907 has 2 divisors, whose sum is σ = 18919908. Its totient is φ = 18919906.

The previous prime is 18919891. The next prime is 18919939. The reversal of 18919907 is 70991981.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18919907 - 2⁴ = 18919891 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18919007) 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, 9459953 + 9459954.

It is an arithmetic number, because the mean of its divisors is an integer number (9459954).

Almost surely, 2^18919907 is an apocalyptic number.

18919907 is a deficient number, since it is larger than the sum of its proper divisors (1).

18919907 is an equidigital number, since it uses as much as digits as its factorization.

18919907 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40824, while the sum is 44.

The square root of 18919907 is about 4349.7019438118. The cubic root of 18919907 is about 266.4646888976.

The spelling of 18919907 in words is "eighteen million, nine hundred nineteen thousand, nine hundred seven".