18726289 has 2 divisors, whose sum is σ = 18726290. Its totient is φ = 18726288.

The previous prime is 18726287. The next prime is 18726311. The reversal of 18726289 is 98262781.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15366400 + 3359889 = 3920^2 + 1833^2 .

It is an emirp because it is prime and its reverse (98262781) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18726289 - 2¹ = 18726287 is a prime.

Together with 18726287, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (18726283) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9363144 + 9363145.

It is an arithmetic number, because the mean of its divisors is an integer number (9363145).

Almost surely, 2^18726289 is an apocalyptic number.

It is an amenable number.

18726289 is a deficient number, since it is larger than the sum of its proper divisors (1).

18726289 is an equidigital number, since it uses as much as digits as its factorization.

18726289 is an evil number, because the sum of its binary digits is even.

The product of its digits is 96768, while the sum is 43.

The square root of 18726289 is about 4327.3882423466. The cubic root of 18726289 is about 265.5526097359.

The spelling of 18726289 in words is "eighteen million, seven hundred twenty-six thousand, two hundred eighty-nine".