18112813 has 4 divisors (see below), whose sum is σ = 18498240. Its totient is φ = 17727388.

The previous prime is 18112793. The next prime is 18112817. The reversal of 18112813 is 31821181.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18112813 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18112817) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 192643 + ... + 192736.

It is an arithmetic number, because the mean of its divisors is an integer number (4624560).

Almost surely, 2^18112813 is an apocalyptic number.

It is an amenable number.

18112813 is a deficient number, since it is larger than the sum of its proper divisors (385427).

18112813 is an equidigital number, since it uses as much as digits as its factorization.

18112813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 385426.

The product of its digits is 384, while the sum is 25.

The square root of 18112813 is about 4255.9150602426. The cubic root of 18112813 is about 262.6205064240.

Adding to 18112813 its reverse (31821181), we get a palindrome (49933994).

It can be divided in two parts, 1811 and 2813, that added together give a square (4624 = 68²).

The spelling of 18112813 in words is "eighteen million, one hundred twelve thousand, eight hundred thirteen".