166694081 has 2 divisors, whose sum is σ = 166694082. Its totient is φ = 166694080.

The previous prime is 166694071. The next prime is 166694083. The reversal of 166694081 is 180496661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 128142400 + 38551681 = 11320^2 + 6209^2 .

It is a cyclic number.

It is not a de Polignac number, because 166694081 - 2¹⁴ = 166677697 is a prime.

It is a super-2 number, since 2×166694081² = 55573833280869122, which contains 22 as substring.

Together with 166694083, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (166694083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83347040 + 83347041.

It is an arithmetic number, because the mean of its divisors is an integer number (83347041).

Almost surely, 2^166694081 is an apocalyptic number.

It is an amenable number.

166694081 is a deficient number, since it is larger than the sum of its proper divisors (1).

166694081 is an equidigital number, since it uses as much as digits as its factorization.

166694081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 62208, while the sum is 41.

The square root of 166694081 is about 12911.0061962653. The cubic root of 166694081 is about 550.3513798730.

The spelling of 166694081 in words is "one hundred sixty-six million, six hundred ninety-four thousand, eighty-one".