18894989 has 2 divisors, whose sum is σ = 18894990. Its totient is φ = 18894988.

The previous prime is 18894971. The next prime is 18894991. The reversal of 18894989 is 98949881.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18852964 + 42025 = 4342^2 + 205^2 .

It is a cyclic number.

It is not a de Polignac number, because 18894989 - 2¹⁶ = 18829453 is a prime.

Together with 18894991, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18894919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9447494 + 9447495.

It is an arithmetic number, because the mean of its divisors is an integer number (9447495).

Almost surely, 2^18894989 is an apocalyptic number.

It is an amenable number.

18894989 is a deficient number, since it is larger than the sum of its proper divisors (1).

18894989 is an equidigital number, since it uses as much as digits as its factorization.

18894989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1492992, while the sum is 56.

The square root of 18894989 is about 4346.8366658985. The cubic root of 18894989 is about 266.3476572412.

The spelling of 18894989 in words is "eighteen million, eight hundred ninety-four thousand, nine hundred eighty-nine".