166336981 has 2 divisors, whose sum is σ = 166336982. Its totient is φ = 166336980.

The previous prime is 166336939. The next prime is 166336987. The reversal of 166336981 is 189633661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 107952100 + 58384881 = 10390^2 + 7641^2 .

It is a cyclic number.

It is not a de Polignac number, because 166336981 - 2¹⁵ = 166304213 is a prime.

It is a super-2 number, since 2×166336981² = 55335982496388722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166336987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83168490 + 83168491.

It is an arithmetic number, because the mean of its divisors is an integer number (83168491).

Almost surely, 2^166336981 is an apocalyptic number.

It is an amenable number.

166336981 is a deficient number, since it is larger than the sum of its proper divisors (1).

166336981 is an equidigital number, since it uses as much as digits as its factorization.

166336981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 139968, while the sum is 43.

The square root of 166336981 is about 12897.1694956684. The cubic root of 166336981 is about 549.9581025936.

The spelling of 166336981 in words is "one hundred sixty-six million, three hundred thirty-six thousand, nine hundred eighty-one".