166534321 has 4 divisors (see below), whose sum is σ = 169676532. Its totient is φ = 163392112.

The previous prime is 166534309. The next prime is 166534343. The reversal of 166534321 is 123435661.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 60217600 + 106316721 = 7760^2 + 10311^2 .

It is a cyclic number.

It is not a de Polignac number, because 166534321 - 2¹¹ = 166532273 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (166534391) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1571026 + ... + 1571131.

It is an arithmetic number, because the mean of its divisors is an integer number (42419133).

Almost surely, 2^166534321 is an apocalyptic number.

It is an amenable number.

166534321 is a deficient number, since it is larger than the sum of its proper divisors (3142211).

166534321 is an equidigital number, since it uses as much as digits as its factorization.

166534321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3142210.

The product of its digits is 12960, while the sum is 31.

The square root of 166534321 is about 12904.8177437731. The cubic root of 166534321 is about 550.1755043214.

Adding to 166534321 its reverse (123435661), we get a palindrome (289969982).

The spelling of 166534321 in words is "one hundred sixty-six million, five hundred thirty-four thousand, three hundred twenty-one".