18131845 has 8 divisors (see below), whose sum is σ = 21821976. Its totient is φ = 14462976.

The previous prime is 18131831. The next prime is 18131857. The reversal of 18131845 is 54813181.

It can be written as a sum of positive squares in 4 ways, for example, as 298116 + 17833729 = 546^2 + 4223^2 .

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 18131845 - 2²¹ = 16034693 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 in 7 ways as a sum of consecutive naturals, for example, 3372 + ... + 6901.

It is an arithmetic number, because the mean of its divisors is an integer number (2727747).

Almost surely, 2^18131845 is an apocalyptic number.

It is an amenable number.

18131845 is a deficient number, since it is larger than the sum of its proper divisors (3690131).

18131845 is a wasteful number, since it uses less digits than its factorization.

18131845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10631.

The product of its digits is 3840, while the sum is 31.

The square root of 18131845 is about 4258.1504200768. The cubic root of 18131845 is about 262.7124568734.

The spelling of 18131845 in words is "eighteen million, one hundred thirty-one thousand, eight hundred forty-five".