18189637 has 2 divisors, whose sum is σ = 18189638. Its totient is φ = 18189636.

The previous prime is 18189623. The next prime is 18189667. The reversal of 18189637 is 73698181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15610401 + 2579236 = 3951^2 + 1606^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18189637 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18189593 and 18189602.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18189617) 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, 9094818 + 9094819.

It is an arithmetic number, because the mean of its divisors is an integer number (9094819).

Almost surely, 2^18189637 is an apocalyptic number.

It is an amenable number.

18189637 is a deficient number, since it is larger than the sum of its proper divisors (1).

18189637 is an equidigital number, since it uses as much as digits as its factorization.

18189637 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 72576, while the sum is 43.

The square root of 18189637 is about 4264.9310662659. The cubic root of 18189637 is about 262.9912771134.

The spelling of 18189637 in words is "eighteen million, one hundred eighty-nine thousand, six hundred thirty-seven".