222116561 has 8 divisors (see below), whose sum is σ = 223438824. Its totient is φ = 220798720.

The previous prime is 222116537. The next prime is 222116569. The reversal of 222116561 is 165611222.

It can be written as a sum of positive squares in 4 ways, for example, as 13140625 + 208975936 = 3625^2 + 14456^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-222116561 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 222116561.

It is not an unprimeable number, because it can be changed into a prime (222116569) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 162521 + ... + 163881.

It is an arithmetic number, because the mean of its divisors is an integer number (27929853).

Almost surely, 2^222116561 is an apocalyptic number.

It is an amenable number.

222116561 is a deficient number, since it is larger than the sum of its proper divisors (1322263).

222116561 is a wasteful number, since it uses less digits than its factorization.

222116561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2211.

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

The square root of 222116561 is about 14903.5754434968. The cubic root of 222116561 is about 605.6108494668.

Adding to 222116561 its reverse (165611222), we get a palindrome (387727783).

The spelling of 222116561 in words is "two hundred twenty-two million, one hundred sixteen thousand, five hundred sixty-one".