18868513 has 2 divisors, whose sum is σ = 18868514. Its totient is φ = 18868512.

The previous prime is 18868511. The next prime is 18868519. The reversal of 18868513 is 31586881.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15116544 + 3751969 = 3888^2 + 1937^2 .

It is a cyclic number.

It is not a de Polignac number, because 18868513 - 2¹ = 18868511 is a prime.

Together with 18868511, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (18868511) 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 as a sum of consecutive naturals, namely, 9434256 + 9434257.

It is an arithmetic number, because the mean of its divisors is an integer number (9434257).

Almost surely, 2^18868513 is an apocalyptic number.

It is an amenable number.

18868513 is a deficient number, since it is larger than the sum of its proper divisors (1).

18868513 is an equidigital number, since it uses as much as digits as its factorization.

18868513 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 46080, while the sum is 40.

The square root of 18868513 is about 4343.7901652819. The cubic root of 18868513 is about 266.2231953736.

The spelling of 18868513 in words is "eighteen million, eight hundred sixty-eight thousand, five hundred thirteen".