18916589 has 2 divisors, whose sum is σ = 18916590. Its totient is φ = 18916588.

The previous prime is 18916577. The next prime is 18916619. The reversal of 18916589 is 98561981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16467364 + 2449225 = 4058^2 + 1565^2 .

It is a cyclic number.

It is not a de Polignac number, because 18916589 - 2²⁴ = 2139373 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18916519) 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, 9458294 + 9458295.

It is an arithmetic number, because the mean of its divisors is an integer number (9458295).

Almost surely, 2^18916589 is an apocalyptic number.

It is an amenable number.

18916589 is a deficient number, since it is larger than the sum of its proper divisors (1).

18916589 is an equidigital number, since it uses as much as digits as its factorization.

18916589 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 155520, while the sum is 47.

The square root of 18916589 is about 4349.3205216447. The cubic root of 18916589 is about 266.4491112747.

The spelling of 18916589 in words is "eighteen million, nine hundred sixteen thousand, five hundred eighty-nine".