166861729 has 2 divisors, whose sum is σ = 166861730. Its totient is φ = 166861728.

The previous prime is 166861727. The next prime is 166861733. The reversal of 166861729 is 927168661.

166861729 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 163251729 + 3610000 = 12777^2 + 1900^2 .

It is a cyclic number.

It is not a de Polignac number, because 166861729 - 2¹ = 166861727 is a prime.

Together with 166861727, 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 (166861727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83430864 + 83430865.

It is an arithmetic number, because the mean of its divisors is an integer number (83430865).

Almost surely, 2^166861729 is an apocalyptic number.

It is an amenable number.

166861729 is a deficient number, since it is larger than the sum of its proper divisors (1).

166861729 is an equidigital number, since it uses as much as digits as its factorization.

166861729 is an evil number, because the sum of its binary digits is even.

The product of its digits is 217728, while the sum is 46.

The square root of 166861729 is about 12917.4970098700. The cubic root of 166861729 is about 550.5358183240.

The spelling of 166861729 in words is "one hundred sixty-six million, eight hundred sixty-one thousand, seven hundred twenty-nine".