166534021 has 2 divisors, whose sum is σ = 166534022. Its totient is φ = 166534020.

The previous prime is 166534001. The next prime is 166534063. The reversal of 166534021 is 120435661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 133056225 + 33477796 = 11535^2 + 5786^2 .

It is a cyclic number.

It is not a de Polignac number, because 166534021 - 2⁷ = 166533893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166534001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83267010 + 83267011.

It is an arithmetic number, because the mean of its divisors is an integer number (83267011).

Almost surely, 2^166534021 is an apocalyptic number.

It is an amenable number.

166534021 is a deficient number, since it is larger than the sum of its proper divisors (1).

166534021 is an equidigital number, since it uses as much as digits as its factorization.

166534021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 166534021 is about 12904.8061202019. The cubic root of 166534021 is about 550.1751739536.

Adding to 166534021 its reverse (120435661), we get a palindrome (286969682).

The spelling of 166534021 in words is "one hundred sixty-six million, five hundred thirty-four thousand, twenty-one".