221666666656556 has 12 divisors (see below), whose sum is σ = 423181818162600. Its totient is φ = 100757575752960.

The previous prime is 221666666656541. The next prime is 221666666656681. The reversal of 221666666656556 is 655656666666122.

It is a super-2 number, since 2×221666666656556² (a number of 29 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2518939393781 + ... + 2518939393868.

It is an arithmetic number, because the mean of its divisors is an integer number (35265151513550).

Almost surely, 2^{221666666656556} is an apocalyptic number.

It is an amenable number.

221666666656556 is a deficient number, since it is larger than the sum of its proper divisors (201515151506044).

221666666656556 is a wasteful number, since it uses less digits than its factorization.

221666666656556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5037878787664 (or 5037878787662 counting only the distinct ones).

The product of its digits is 5038848000, while the sum is 74.

It can be divided in two parts, 221666666 and 656556, that added together give a palindrome (222323222).

The spelling of 221666666656556 in words is "two hundred twenty-one trillion, six hundred sixty-six billion, six hundred sixty-six million, six hundred fifty-six thousand, five hundred fifty-six".