168646999861 has 2 divisors, whose sum is σ = 168646999862. Its totient is φ = 168646999860.

The previous prime is 168646999841. The next prime is 168646999897. The reversal of 168646999861 is 168999646861.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 88738452100 + 79908547761 = 297890^2 + 282681^2 .

It is a cyclic number.

It is not a de Polignac number, because 168646999861 - 2²⁷ = 168512782133 is a prime.

It is a super-2 number, since 2×168646999861² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (168646999811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84323499930 + 84323499931.

It is an arithmetic number, because the mean of its divisors is an integer number (84323499931).

Almost surely, 2^168646999861 is an apocalyptic number.

It is an amenable number.

168646999861 is a deficient number, since it is larger than the sum of its proper divisors (1).

168646999861 is an equidigital number, since it uses as much as digits as its factorization.

168646999861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 241864704, while the sum is 73.

The spelling of 168646999861 in words is "one hundred sixty-eight billion, six hundred forty-six million, nine hundred ninety-nine thousand, eight hundred sixty-one".