18687337417817 has 2 divisors, whose sum is σ = 18687337417818. Its totient is φ = 18687337417816.

The previous prime is 18687337417703. The next prime is 18687337417843. The reversal of 18687337417817 is 71871473378681.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12388562628121 + 6298774789696 = 3519739^2 + 2509736^2 .

It is a cyclic number.

It is not a de Polignac number, because 18687337417817 - 2¹⁸ = 18687337155673 is a prime.

It is not a weakly prime, because it can be changed into another prime (18687337417877) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9343668708908 + 9343668708909.

It is an arithmetic number, because the mean of its divisors is an integer number (9343668708909).

Almost surely, 2^{18687337417817} is an apocalyptic number.

It is an amenable number.

18687337417817 is a deficient number, since it is larger than the sum of its proper divisors (1).

18687337417817 is an equidigital number, since it uses as much as digits as its factorization.

18687337417817 is an evil number, because the sum of its binary digits is even.

The product of its digits is 265531392, while the sum is 71.

The spelling of 18687337417817 in words is "eighteen trillion, six hundred eighty-seven billion, three hundred thirty-seven million, four hundred seventeen thousand, eight hundred seventeen".