166321879 has 2 divisors, whose sum is σ = 166321880. Its totient is φ = 166321878.

The previous prime is 166321849. The next prime is 166321889. The reversal of 166321879 is 978123661.

It is a strong prime.

It is an emirp because it is prime and its reverse (978123661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 166321879 - 2¹³ = 166313687 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166321849) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83160939 + 83160940.

It is an arithmetic number, because the mean of its divisors is an integer number (83160940).

Almost surely, 2^166321879 is an apocalyptic number.

166321879 is a deficient number, since it is larger than the sum of its proper divisors (1).

166321879 is an equidigital number, since it uses as much as digits as its factorization.

166321879 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108864, while the sum is 43.

The square root of 166321879 is about 12896.5840050767. The cubic root of 166321879 is about 549.9414582319.

The spelling of 166321879 in words is "one hundred sixty-six million, three hundred twenty-one thousand, eight hundred seventy-nine".