221979599966 has 16 divisors (see below), whose sum is σ = 337448140800. Its totient is φ = 109499086008.

The previous prime is 221979599957. The next prime is 221979599971. The reversal of 221979599966 is 669995979122.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 221979599893 and 221979599902.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 347150 + ... + 751313.

It is an arithmetic number, because the mean of its divisors is an integer number (21090508800).

Almost surely, 2^221979599966 is an apocalyptic number.

221979599966 is a deficient number, since it is larger than the sum of its proper divisors (115468540834).

221979599966 is a wasteful number, since it uses less digits than its factorization.

221979599966 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1099823.

The product of its digits is 297606960, while the sum is 74.

The spelling of 221979599966 in words is "two hundred twenty-one billion, nine hundred seventy-nine million, five hundred ninety-nine thousand, nine hundred sixty-six".