166435221 has 4 divisors (see below), whose sum is σ = 221913632. Its totient is φ = 110956812.

The previous prime is 166435207. The next prime is 166435223. The reversal of 166435221 is 122534661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 166435221 - 2⁵ = 166435189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166435223) 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, 27739201 + ... + 27739206.

It is an arithmetic number, because the mean of its divisors is an integer number (55478408).

Almost surely, 2^166435221 is an apocalyptic number.

It is an amenable number.

166435221 is a deficient number, since it is larger than the sum of its proper divisors (55478411).

166435221 is an equidigital number, since it uses as much as digits as its factorization.

166435221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55478410.

The product of its digits is 8640, while the sum is 30.

The square root of 166435221 is about 12900.9775211028. The cubic root of 166435221 is about 550.0663512238.

Adding to 166435221 its reverse (122534661), we get a palindrome (288969882).

The spelling of 166435221 in words is "one hundred sixty-six million, four hundred thirty-five thousand, two hundred twenty-one".