166441344232021 has 4 divisors (see below), whose sum is σ = 166441678074700. Its totient is φ = 166441010389344.

The previous prime is 166441344231959. The next prime is 166441344232057. The reversal of 166441344232021 is 120232443144661.

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 27312006235921 + 139129337996100 = 5226089^2 + 11795310^2 .

It is a cyclic number.

It is not a de Polignac number, because 166441344232021 - 2⁹ = 166441344231509 is a prime.

It is a super-2 number, since 2×166441344232021² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166441344232091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 166172376 + ... + 167170993.

It is an arithmetic number, because the mean of its divisors is an integer number (41610419518675).

Almost surely, 2^{166441344232021} is an apocalyptic number.

It is an amenable number.

166441344232021 is a deficient number, since it is larger than the sum of its proper divisors (333842679).

166441344232021 is an equidigital number, since it uses as much as digits as its factorization.

166441344232021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333842678.

The product of its (nonzero) digits is 663552, while the sum is 43.

Adding to 166441344232021 its reverse (120232443144661), we get a palindrome (286673787376682).

The spelling of 166441344232021 in words is "one hundred sixty-six trillion, four hundred forty-one billion, three hundred forty-four million, two hundred thirty-two thousand, twenty-one".