166243121 has 4 divisors (see below), whose sum is σ = 181356144. Its totient is φ = 151130100.

The previous prime is 166243093. The next prime is 166243169. The reversal of 166243121 is 121342661.

166243121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 166243121 - 2¹⁴ = 166226737 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166243171) 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, 7556495 + ... + 7556516.

It is an arithmetic number, because the mean of its divisors is an integer number (45339036).

Almost surely, 2^166243121 is an apocalyptic number.

166243121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

166243121 is a deficient number, since it is larger than the sum of its proper divisors (15113023).

166243121 is a wasteful number, since it uses less digits than its factorization.

166243121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15113022.

The product of its digits is 1728, while the sum is 26.

The square root of 166243121 is about 12893.5301992899. The cubic root of 166243121 is about 549.8546403741.

Adding to 166243121 its reverse (121342661), we get a palindrome (287585782).

The spelling of 166243121 in words is "one hundred sixty-six million, two hundred forty-three thousand, one hundred twenty-one".