166621219 has 2 divisors, whose sum is σ = 166621220. Its totient is φ = 166621218.

The previous prime is 166621201. The next prime is 166621237. The reversal of 166621219 is 912126661.

166621219 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a balanced prime because it is at equal distance from previous prime (166621201) and next prime (166621237).

It is a cyclic number.

It is not a de Polignac number, because 166621219 - 2¹⁷ = 166490147 is a prime.

It is a super-2 number, since 2×166621219² = 55525261242091922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (166621289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83310609 + 83310610.

It is an arithmetic number, because the mean of its divisors is an integer number (83310610).

Almost surely, 2^166621219 is an apocalyptic number.

166621219 is a deficient number, since it is larger than the sum of its proper divisors (1).

166621219 is an equidigital number, since it uses as much as digits as its factorization.

166621219 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7776, while the sum is 34.

The square root of 166621219 is about 12908.1841867863. The cubic root of 166621219 is about 550.2711819720.

The spelling of 166621219 in words is "one hundred sixty-six million, six hundred twenty-one thousand, two hundred nineteen".