221666500730 has 16 divisors (see below), whose sum is σ = 399363440040. Its totient is φ = 88585769472.

The previous prime is 221666500687. The next prime is 221666500739. The reversal of 221666500730 is 37005666122.

221666500730 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 4 ways, for example, as 174315435121 + 47351065609 = 417511^2 + 217603^2 .

It is not an unprimeable number, because it can be changed into a prime (221666500739) 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 7 ways as a sum of consecutive naturals, for example, 10092335 + ... + 10114274.

Almost surely, 2^221666500730 is an apocalyptic number.

221666500730 is a deficient number, since it is larger than the sum of its proper divisors (177696939310).

221666500730 is a wasteful number, since it uses less digits than its factorization.

221666500730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20207713.

The product of its (nonzero) digits is 90720, while the sum is 38.

The spelling of 221666500730 in words is "two hundred twenty-one billion, six hundred sixty-six million, five hundred thousand, seven hundred thirty".