16685186868481 has 2 divisors, whose sum is σ = 16685186868482. Its totient is φ = 16685186868480.

The previous prime is 16685186868473. The next prime is 16685186868509. The reversal of 16685186868481 is 18486868158661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9556500466881 + 7128686401600 = 3091359^2 + 2669960^2 .

It is a cyclic number.

It is not a de Polignac number, because 16685186868481 - 2³ = 16685186868473 is a prime.

It is a super-2 number, since 2×16685186868481² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 16685186868398 and 16685186868407.

It is not a weakly prime, because it can be changed into another prime (16685186268481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8342593434240 + 8342593434241.

It is an arithmetic number, because the mean of its divisors is an integer number (8342593434241).

Almost surely, 2^{16685186868481} is an apocalyptic number.

It is an amenable number.

16685186868481 is a deficient number, since it is larger than the sum of its proper divisors (1).

16685186868481 is an equidigital number, since it uses as much as digits as its factorization.

16685186868481 is an evil number, because the sum of its binary digits is even.

The product of its digits is 849346560, while the sum is 76.

The spelling of 16685186868481 in words is "sixteen trillion, six hundred eighty-five billion, one hundred eighty-six million, eight hundred sixty-eight thousand, four hundred eighty-one".