221696666649 has 6 divisors (see below), whose sum is σ = 320228518506. Its totient is φ = 147797777760.

The previous prime is 221696666617. The next prime is 221696666683. The reversal of 221696666649 is 946666696122.

221696666649 is digitally balanced in base 2, because in such base 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., 169772841225 + 51923825424 = 412035^2 + 227868^2 .

It is not a de Polignac number, because 221696666649 - 2⁵ = 221696666617 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221696666249) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12316481472 + ... + 12316481489.

It is an arithmetic number, because the mean of its divisors is an integer number (53371419751).

Almost surely, 2^221696666649 is an apocalyptic number.

It is an amenable number.

221696666649 is a deficient number, since it is larger than the sum of its proper divisors (98531851857).

221696666649 is a wasteful number, since it uses less digits than its factorization.

221696666649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24632962967 (or 24632962964 counting only the distinct ones).

The product of its digits is 60466176, while the sum is 63.

The spelling of 221696666649 in words is "two hundred twenty-one billion, six hundred ninety-six million, six hundred sixty-six thousand, six hundred forty-nine".