18136531 has 8 divisors (see below), whose sum is σ = 20771424. Its totient is φ = 15512640.

The previous prime is 18136529. The next prime is 18136537. The reversal of 18136531 is 13563181.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18136531 - 2¹ = 18136529 is a prime.

It is a super-2 number, since 2×18136531² = 657867513427922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18136531.

It is not an unprimeable number, because it can be changed into a prime (18136537) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1161 + ... + 6133.

It is an arithmetic number, because the mean of its divisors is an integer number (2596428).

Almost surely, 2^18136531 is an apocalyptic number.

18136531 is a deficient number, since it is larger than the sum of its proper divisors (2634893).

18136531 is an equidigital number, since it uses as much as digits as its factorization.

18136531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5501.

The product of its digits is 2160, while the sum is 28.

The square root of 18136531 is about 4258.7006234296. The cubic root of 18136531 is about 262.7350867553.

The spelling of 18136531 in words is "eighteen million, one hundred thirty-six thousand, five hundred thirty-one".