166215122 has 4 divisors (see below), whose sum is σ = 249322686. Its totient is φ = 83107560.

The previous prime is 166215109. The next prime is 166215139. The reversal of 166215122 is 221512661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 221512661 = 1193 ⋅185677.

It can be written as a sum of positive squares in only one way, i.e., 85951441 + 80263681 = 9271^2 + 8959^2 .

It is a junction number, because it is equal to n+sod(n) for n = 166215091 and 166215100.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41553779 + ... + 41553782.

Almost surely, 2^166215122 is an apocalyptic number.

166215122 is a deficient number, since it is larger than the sum of its proper divisors (83107564).

166215122 is an equidigital number, since it uses as much as digits as its factorization.

166215122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83107563.

The product of its digits is 1440, while the sum is 26.

The square root of 166215122 is about 12892.4443764555. Note that the first 3 decimals coincide. The cubic root of 166215122 is about 549.8237694337.

Adding to 166215122 its reverse (221512661), we get a palindrome (387727783).

The spelling of 166215122 in words is "one hundred sixty-six million, two hundred fifteen thousand, one hundred twenty-two".