166221521670122 has 4 divisors (see below), whose sum is σ = 249332282505186. Its totient is φ = 83110760835060.

The previous prime is 166221521670101. The next prime is 166221521670131. The reversal of 166221521670122 is 221076125122661.

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

It can be written as a sum of positive squares in only one way, i.e., 130484906154001 + 35736615516121 = 11422999^2 + 5978011^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41555380417529 + ... + 41555380417532.

Almost surely, 2^{166221521670122} is an apocalyptic number.

166221521670122 is a deficient number, since it is larger than the sum of its proper divisors (83110760835064).

166221521670122 is an equidigital number, since it uses as much as digits as its factorization.

166221521670122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83110760835063.

The product of its (nonzero) digits is 241920, while the sum is 44.

Adding to 166221521670122 its reverse (221076125122661), we get a palindrome (387297646792783).

The spelling of 166221521670122 in words is "one hundred sixty-six trillion, two hundred twenty-one billion, five hundred twenty-one million, six hundred seventy thousand, one hundred twenty-two".