18040731 has 8 divisors (see below), whose sum is σ = 24244224. Its totient is φ = 11932200.

The previous prime is 18040703. The next prime is 18040751. The reversal of 18040731 is 13704081.

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

It is not a de Polignac number, because 18040731 - 2¹⁵ = 18007963 is a prime.

It is a super-2 number, since 2×18040731² = 650935950028722, which contains 22 as substring.

It is a plaindrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (18040751) 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 7 ways as a sum of consecutive naturals, for example, 23295 + ... + 24056.

It is an arithmetic number, because the mean of its divisors is an integer number (3030528).

Almost surely, 2^18040731 is an apocalyptic number.

18040731 is a deficient number, since it is larger than the sum of its proper divisors (6203493).

18040731 is a wasteful number, since it uses less digits than its factorization.

18040731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47481.

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 18040731 is about 4247.4381690614. The cubic root of 18040731 is about 262.2716672044.

The spelling of 18040731 in words is "eighteen million, forty thousand, seven hundred thirty-one".