18768817 has 2 divisors, whose sum is σ = 18768818. Its totient is φ = 18768816.

The previous prime is 18768809. The next prime is 18768859. The reversal of 18768817 is 71886781.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14107536 + 4661281 = 3756^2 + 2159^2 .

It is an emirp because it is prime and its reverse (71886781) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18768817 - 2³ = 18768809 is a prime.

It is not a weakly prime, because it can be changed into another prime (18768317) 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, 9384408 + 9384409.

It is an arithmetic number, because the mean of its divisors is an integer number (9384409).

Almost surely, 2^18768817 is an apocalyptic number.

It is an amenable number.

18768817 is a deficient number, since it is larger than the sum of its proper divisors (1).

18768817 is an equidigital number, since it uses as much as digits as its factorization.

18768817 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 150528, while the sum is 46.

The square root of 18768817 is about 4332.2992740576. The cubic root of 18768817 is about 265.7534838995.

The spelling of 18768817 in words is "eighteen million, seven hundred sixty-eight thousand, eight hundred seventeen".