166873121 has 2 divisors, whose sum is σ = 166873122. Its totient is φ = 166873120.

The previous prime is 166873117. The next prime is 166873123. The reversal of 166873121 is 121378661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 153264400 + 13608721 = 12380^2 + 3689^2 .

It is an emirp because it is prime and its reverse (121378661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 166873121 - 2² = 166873117 is a prime.

It is a Sophie Germain prime.

Together with 166873123, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is equal to p_9337823 and since 166873121 and 9337823 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (166873123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83436560 + 83436561.

It is an arithmetic number, because the mean of its divisors is an integer number (83436561).

Almost surely, 2^166873121 is an apocalyptic number.

It is an amenable number.

166873121 is a deficient number, since it is larger than the sum of its proper divisors (1).

166873121 is an equidigital number, since it uses as much as digits as its factorization.

166873121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12096, while the sum is 35.

The square root of 166873121 is about 12917.9379546428. The cubic root of 166873121 is about 550.5483467837.

The spelling of 166873121 in words is "one hundred sixty-six million, eight hundred seventy-three thousand, one hundred twenty-one".