18908623 has 2 divisors, whose sum is σ = 18908624. Its totient is φ = 18908622.

The previous prime is 18908621. The next prime is 18908639. The reversal of 18908623 is 32680981.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18908623 - 2¹ = 18908621 is a prime.

It is a super-2 number, since 2×18908623² = 715072047512258, which contains 22 as substring.

Together with 18908621, 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 (18908621) 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, 9454311 + 9454312.

It is an arithmetic number, because the mean of its divisors is an integer number (9454312).

Almost surely, 2^18908623 is an apocalyptic number.

18908623 is a deficient number, since it is larger than the sum of its proper divisors (1).

18908623 is an equidigital number, since it uses as much as digits as its factorization.

18908623 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 18908623 is about 4348.4046499837. The cubic root of 18908623 is about 266.4117043964.

The spelling of 18908623 in words is "eighteen million, nine hundred eight thousand, six hundred twenty-three".