18909413 has 2 divisors, whose sum is σ = 18909414. Its totient is φ = 18909412.

The previous prime is 18909403. The next prime is 18909431. The reversal of 18909413 is 31490981.

Together with next prime (18909431) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18164644 + 744769 = 4262^2 + 863^2 .

It is a cyclic number.

It is not a de Polignac number, because 18909413 - 2¹⁰ = 18908389 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18909403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9454706 + 9454707.

It is an arithmetic number, because the mean of its divisors is an integer number (9454707).

Almost surely, 2^18909413 is an apocalyptic number.

It is an amenable number.

18909413 is a deficient number, since it is larger than the sum of its proper divisors (1).

18909413 is an equidigital number, since it uses as much as digits as its factorization.

18909413 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7776, while the sum is 35.

The square root of 18909413 is about 4348.4954869472. The cubic root of 18909413 is about 266.4154145610.

The spelling of 18909413 in words is "eighteen million, nine hundred nine thousand, four hundred thirteen".