18217013 has 4 divisors (see below), whose sum is σ = 19288620. Its totient is φ = 17145408.

The previous prime is 18216973. The next prime is 18217019. The reversal of 18217013 is 31071281.

It is a happy number.

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 5414929 + 12802084 = 2327^2 + 3578^2 .

It is a cyclic number.

It is not a de Polignac number, because 18217013 - 2¹⁴ = 18200629 is a prime.

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 18217013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18217019) 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, 535778 + ... + 535811.

It is an arithmetic number, because the mean of its divisors is an integer number (4822155).

Almost surely, 2^18217013 is an apocalyptic number.

It is an amenable number.

18217013 is a deficient number, since it is larger than the sum of its proper divisors (1071607).

18217013 is a wasteful number, since it uses less digits than its factorization.

18217013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1071606.

The product of its (nonzero) digits is 336, while the sum is 23.

The square root of 18217013 is about 4268.1392901357. The cubic root of 18217013 is about 263.1231478102.

Adding to 18217013 its reverse (31071281), we get a palindrome (49288294).

The spelling of 18217013 in words is "eighteen million, two hundred seventeen thousand, thirteen".