18756989 has 2 divisors, whose sum is σ = 18756990. Its totient is φ = 18756988.

The previous prime is 18756949. The next prime is 18757007. The reversal of 18756989 is 98965781.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14100025 + 4656964 = 3755^2 + 2158^2 .

It is an emirp because it is prime and its reverse (98965781) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18756989 - 2²⁴ = 1979773 is a prime.

It is a super-2 number, since 2×18756989² = 703649272692242, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 18756989.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18756919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9378494 + 9378495.

It is an arithmetic number, because the mean of its divisors is an integer number (9378495).

Almost surely, 2^18756989 is an apocalyptic number.

It is an amenable number.

18756989 is a deficient number, since it is larger than the sum of its proper divisors (1).

18756989 is an equidigital number, since it uses as much as digits as its factorization.

18756989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1088640, while the sum is 53.

The square root of 18756989 is about 4330.9339639390. The cubic root of 18756989 is about 265.6976467319.

The spelling of 18756989 in words is "eighteen million, seven hundred fifty-six thousand, nine hundred eighty-nine".