216422645561 has 16 divisors (see below), whose sum is σ = 221099673600. Its totient is φ = 211801808400.

The previous prime is 216422645521. The next prime is 216422645597. The reversal of 216422645561 is 165546224612.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216422645561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216422645521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4373246 + ... + 4422456.

It is an arithmetic number, because the mean of its divisors is an integer number (13818729600).

Almost surely, 2^216422645561 is an apocalyptic number.

It is an amenable number.

216422645561 is a deficient number, since it is larger than the sum of its proper divisors (4677028039).

216422645561 is a wasteful number, since it uses less digits than its factorization.

216422645561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49780.

The product of its digits is 691200, while the sum is 44.

The spelling of 216422645561 in words is "two hundred sixteen billion, four hundred twenty-two million, six hundred forty-five thousand, five hundred sixty-one".