18081137 has 4 divisors (see below), whose sum is σ = 18095220. Its totient is φ = 18067056.

The previous prime is 18081131. The next prime is 18081139. The reversal of 18081137 is 73118081.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 474721 + 17606416 = 689^2 + 4196^2 .

It is a cyclic number.

It is not a de Polignac number, because 18081137 - 2¹² = 18077041 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18081131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4898 + ... + 7755.

It is an arithmetic number, because the mean of its divisors is an integer number (4523805).

Almost surely, 2^18081137 is an apocalyptic number.

It is an amenable number.

18081137 is a deficient number, since it is larger than the sum of its proper divisors (14083).

18081137 is a wasteful number, since it uses less digits than its factorization.

18081137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14082.

The product of its (nonzero) digits is 1344, while the sum is 29.

The square root of 18081137 is about 4252.1920229453. The cubic root of 18081137 is about 262.4673253359.

The spelling of 18081137 in words is "eighteen million, eighty-one thousand, one hundred thirty-seven".