18708013 has 4 divisors (see below), whose sum is σ = 19164348. Its totient is φ = 18251680.

The previous prime is 18707971. The next prime is 18708017. The reversal of 18708013 is 31080781.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31080781 = 61 ⋅509521.

It can be written as a sum of positive squares in 2 ways, for example, as 9815689 + 8892324 = 3133^2 + 2982^2 .

It is a cyclic number.

It is not a de Polignac number, because 18708013 - 2⁹ = 18707501 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 (18708017) 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, 228106 + ... + 228187.

It is an arithmetic number, because the mean of its divisors is an integer number (4791087).

Almost surely, 2^18708013 is an apocalyptic number.

It is an amenable number.

18708013 is a deficient number, since it is larger than the sum of its proper divisors (456335).

18708013 is an equidigital number, since it uses as much as digits as its factorization.

18708013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 456334.

The product of its (nonzero) digits is 1344, while the sum is 28.

The square root of 18708013 is about 4325.2760605538. The cubic root of 18708013 is about 265.4661925571.

Adding to 18708013 its reverse (31080781), we get a palindrome (49788794).

The spelling of 18708013 in words is "eighteen million, seven hundred eight thousand, thirteen".