207318856681 has 2 divisors, whose sum is σ = 207318856682. Its totient is φ = 207318856680.

The previous prime is 207318856663. The next prime is 207318856709. The reversal of 207318856681 is 186658813702.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 197327854656 + 9991002025 = 444216^2 + 99955^2 .

It is a cyclic number.

It is not a de Polignac number, because 207318856681 - 2¹⁵ = 207318823913 is a prime.

It is a super-2 number, since 2×207318856681² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (207318856621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103659428340 + 103659428341.

It is an arithmetic number, because the mean of its divisors is an integer number (103659428341).

Almost surely, 2^207318856681 is an apocalyptic number.

It is an amenable number.

207318856681 is a deficient number, since it is larger than the sum of its proper divisors (1).

207318856681 is an equidigital number, since it uses as much as digits as its factorization.

207318856681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3870720, while the sum is 55.

The spelling of 207318856681 in words is "two hundred seven billion, three hundred eighteen million, eight hundred fifty-six thousand, six hundred eighty-one".