18416989 has 2 divisors, whose sum is σ = 18416990. Its totient is φ = 18416988.

The previous prime is 18416977. The next prime is 18417011. The reversal of 18416989 is 98961481.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18344089 + 72900 = 4283^2 + 270^2 .

It is a cyclic number.

It is not a de Polignac number, because 18416989 - 2¹¹ = 18414941 is a prime.

It is a super-2 number, since 2×18416989² = 678370967652242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18416929) 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, 9208494 + 9208495.

It is an arithmetic number, because the mean of its divisors is an integer number (9208495).

Almost surely, 2^18416989 is an apocalyptic number.

It is an amenable number.

18416989 is a deficient number, since it is larger than the sum of its proper divisors (1).

18416989 is an equidigital number, since it uses as much as digits as its factorization.

18416989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 124416, while the sum is 46.

The square root of 18416989 is about 4291.5019515317. The cubic root of 18416989 is about 264.0824514809.

The spelling of 18416989 in words is "eighteen million, four hundred sixteen thousand, nine hundred eighty-nine".