18712513 has 2 divisors, whose sum is σ = 18712514. Its totient is φ = 18712512.

The previous prime is 18712489. The next prime is 18712531. The reversal of 18712513 is 31521781.

18712513 is nontrivially palindromic in base 8.

Together with next prime (18712531) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16257024 + 2455489 = 4032^2 + 1567^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18712513 is a prime.

It is not a weakly prime, because it can be changed into another prime (18712553) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9356256 + 9356257.

It is an arithmetic number, because the mean of its divisors is an integer number (9356257).

Almost surely, 2^18712513 is an apocalyptic number.

It is an amenable number.

18712513 is a deficient number, since it is larger than the sum of its proper divisors (1).

18712513 is an equidigital number, since it uses as much as digits as its factorization.

18712513 is an evil number, because the sum of its binary digits is even.

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

The square root of 18712513 is about 4325.7962272858. The cubic root of 18712513 is about 265.4874758096.

The spelling of 18712513 in words is "eighteen million, seven hundred twelve thousand, five hundred thirteen".