221712122 has 4 divisors (see below), whose sum is σ = 332568186. Its totient is φ = 110856060.

The previous prime is 221712109. The next prime is 221712137. The reversal of 221712122 is 221217122.

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., 208542481 + 13169641 = 14441^2 + 3629^2 .

It is a junction number, because it is equal to n+sod(n) for n = 221712094 and 221712103.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55428029 + ... + 55428032.

Almost surely, 2^221712122 is an apocalyptic number.

221712122 is a deficient number, since it is larger than the sum of its proper divisors (110856064).

221712122 is a wasteful number, since it uses less digits than its factorization.

221712122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110856063.

The product of its digits is 224, while the sum is 20.

The square root of 221712122 is about 14890.0007387508. Note that the first 3 decimals coincide. The cubic root of 221712122 is about 605.2430524012.

Adding to 221712122 its reverse (221217122), we get a palindrome (442929244).

The spelling of 221712122 in words is "two hundred twenty-one million, seven hundred twelve thousand, one hundred twenty-two".