221211716 has 18 divisors (see below), whose sum is σ = 425513550. Its totient is φ = 100550560.

The previous prime is 221211673. The next prime is 221211719. The reversal of 221211716 is 617112122.

221211716 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 195160900 + 26050816 = 13970^2 + 5104^2 .

It is a junction number, because it is equal to n+sod(n) for n = 221211691 and 221211700.

It is not an unprimeable number, because it can be changed into a prime (221211719) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 228041 + ... + 229008.

Almost surely, 2^221211716 is an apocalyptic number.

It is an amenable number.

221211716 is a deficient number, since it is larger than the sum of its proper divisors (204301834).

221211716 is a wasteful number, since it uses less digits than its factorization.

221211716 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 457075 (or 457062 counting only the distinct ones).

The product of its digits is 336, while the sum is 23.

The square root of 221211716 is about 14873.1878223870. The cubic root of 221211716 is about 604.7873632908.

Adding to 221211716 its reverse (617112122), we get a palindrome (838323838).

The spelling of 221211716 in words is "two hundred twenty-one million, two hundred eleven thousand, seven hundred sixteen".