166841881 has 2 divisors, whose sum is σ = 166841882. Its totient is φ = 166841880.

The previous prime is 166841819. The next prime is 166841887. The reversal of 166841881 is 188148661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 88360000 + 78481881 = 9400^2 + 8859^2 .

It is a cyclic number.

It is not a de Polignac number, because 166841881 - 2⁹ = 166841369 is a prime.

It is a super-2 number, since 2×166841881² = 55672426511236322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (166841887) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83420940 + 83420941.

It is an arithmetic number, because the mean of its divisors is an integer number (83420941).

Almost surely, 2^166841881 is an apocalyptic number.

It is an amenable number.

166841881 is a deficient number, since it is larger than the sum of its proper divisors (1).

166841881 is an equidigital number, since it uses as much as digits as its factorization.

166841881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 73728, while the sum is 43.

The square root of 166841881 is about 12916.7287267326. The cubic root of 166841881 is about 550.5139889362.

The spelling of 166841881 in words is "one hundred sixty-six million, eight hundred forty-one thousand, eight hundred eighty-one".