166980661 has 2 divisors, whose sum is σ = 166980662. Its totient is φ = 166980660.

The previous prime is 166980629. The next prime is 166980673. The reversal of 166980661 is 166089661.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 163686436 + 3294225 = 12794^2 + 1815^2 .

It is a cyclic number.

It is not a de Polignac number, because 166980661 - 2⁵ = 166980629 is a prime.

It is a super-2 number, since 2×166980661² = 55765082295993842, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166980691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83490330 + 83490331.

It is an arithmetic number, because the mean of its divisors is an integer number (83490331).

Almost surely, 2^166980661 is an apocalyptic number.

It is an amenable number.

166980661 is a deficient number, since it is larger than the sum of its proper divisors (1).

166980661 is an equidigital number, since it uses as much as digits as its factorization.

166980661 is an odious number, because the sum of its binary digits is odd.

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

The square root of 166980661 is about 12922.0997132819. The cubic root of 166980661 is about 550.6665868277. Note that the first 3 decimals are identical.

The spelling of 166980661 in words is "one hundred sixty-six million, nine hundred eighty thousand, six hundred sixty-one".