18981359 has 2 divisors, whose sum is σ = 18981360. Its totient is φ = 18981358.

The previous prime is 18981343. The next prime is 18981377. The reversal of 18981359 is 95318981.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18981359 - 2⁴ = 18981343 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18981329) 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, 9490679 + 9490680.

It is an arithmetic number, because the mean of its divisors is an integer number (9490680).

Almost surely, 2^18981359 is an apocalyptic number.

18981359 is a deficient number, since it is larger than the sum of its proper divisors (1).

18981359 is an equidigital number, since it uses as much as digits as its factorization.

18981359 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 77760, while the sum is 44.

The square root of 18981359 is about 4356.7601494689. The cubic root of 18981359 is about 266.7528702208.

The spelling of 18981359 in words is "eighteen million, nine hundred eighty-one thousand, three hundred fifty-nine".