166669081 has 2 divisors, whose sum is σ = 166669082. Its totient is φ = 166669080.

The previous prime is 166669049. The next prime is 166669157. The reversal of 166669081 is 180966661.

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., 166410000 + 259081 = 12900^2 + 509^2 .

It is a cyclic number.

It is not a de Polignac number, because 166669081 - 2⁵ = 166669049 is a prime.

It is a super-2 number, since 2×166669081² = 55557165122769122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (166669781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83334540 + 83334541.

It is an arithmetic number, because the mean of its divisors is an integer number (83334541).

Almost surely, 2^166669081 is an apocalyptic number.

It is an amenable number.

166669081 is a deficient number, since it is larger than the sum of its proper divisors (1).

166669081 is an equidigital number, since it uses as much as digits as its factorization.

166669081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 93312, while the sum is 43.

The square root of 166669081 is about 12910.0379937473. The cubic root of 166669081 is about 550.3238654539.

The spelling of 166669081 in words is "one hundred sixty-six million, six hundred sixty-nine thousand, eighty-one".