18215713 has 4 divisors (see below), whose sum is σ = 18377028. Its totient is φ = 18054400.

The previous prime is 18215711. The next prime is 18215731. The reversal of 18215713 is 31751281.

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 9412624 + 8803089 = 3068^2 + 2967^2 .

It is a cyclic number.

It is not a de Polignac number, because 18215713 - 2¹ = 18215711 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18215711) 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, 80488 + ... + 80713.

It is an arithmetic number, because the mean of its divisors is an integer number (4594257).

Almost surely, 2^18215713 is an apocalyptic number.

It is an amenable number.

18215713 is a deficient number, since it is larger than the sum of its proper divisors (161315).

18215713 is a wasteful number, since it uses less digits than its factorization.

18215713 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161314.

The product of its digits is 1680, while the sum is 28.

The square root of 18215713 is about 4267.9869962314. The cubic root of 18215713 is about 263.1168886752.

Adding to 18215713 its reverse (31751281), we get a palindrome (49966994).

The spelling of 18215713 in words is "eighteen million, two hundred fifteen thousand, seven hundred thirteen".