18011009 has 2 divisors, whose sum is σ = 18011010. Its totient is φ = 18011008.

The previous prime is 18010999. The next prime is 18011017. The reversal of 18011009 is 90011081.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14227984 + 3783025 = 3772^2 + 1945^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18011009 is a prime.

It is not a weakly prime, because it can be changed into another prime (18011039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9005504 + 9005505.

It is an arithmetic number, because the mean of its divisors is an integer number (9005505).

Almost surely, 2^18011009 is an apocalyptic number.

It is an amenable number.

18011009 is a deficient number, since it is larger than the sum of its proper divisors (1).

18011009 is an equidigital number, since it uses as much as digits as its factorization.

18011009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 20.

The square root of 18011009 is about 4243.9379118927. The cubic root of 18011009 is about 262.1275576838.

Adding to 18011009 its product of nonzero digits (72), we get a palindrome (18011081).

The spelling of 18011009 in words is "eighteen million, eleven thousand, nine".