166851760081 has 2 divisors, whose sum is σ = 166851760082. Its totient is φ = 166851760080.

The previous prime is 166851760067. The next prime is 166851760109. The reversal of 166851760081 is 180067158661.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 156689305600 + 10162454481 = 395840^2 + 100809^2 .

It is a cyclic number.

It is not a de Polignac number, because 166851760081 - 2¹³ = 166851751889 is a prime.

It is a super-2 number, since 2×166851760081² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (166851760981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83425880040 + 83425880041.

It is an arithmetic number, because the mean of its divisors is an integer number (83425880041).

Almost surely, 2^166851760081 is an apocalyptic number.

It is an amenable number.

166851760081 is a deficient number, since it is larger than the sum of its proper divisors (1).

166851760081 is an equidigital number, since it uses as much as digits as its factorization.

166851760081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 483840, while the sum is 49.

The spelling of 166851760081 in words is "one hundred sixty-six billion, eight hundred fifty-one million, seven hundred sixty thousand, eighty-one".