18722489 has 2 divisors, whose sum is σ = 18722490. Its totient is φ = 18722488.

The previous prime is 18722461. The next prime is 18722503. The reversal of 18722489 is 98422781.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12924025 + 5798464 = 3595^2 + 2408^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18722489 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18722449) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9361244 + 9361245.

It is an arithmetic number, because the mean of its divisors is an integer number (9361245).

Almost surely, 2^18722489 is an apocalyptic number.

It is an amenable number.

18722489 is a deficient number, since it is larger than the sum of its proper divisors (1).

18722489 is an equidigital number, since it uses as much as digits as its factorization.

18722489 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 64512, while the sum is 41.

The square root of 18722489 is about 4326.9491561607. The cubic root of 18722489 is about 265.5346462519.

The spelling of 18722489 in words is "eighteen million, seven hundred twenty-two thousand, four hundred eighty-nine".