221720966 has 8 divisors (see below), whose sum is σ = 347041584. Its totient is φ = 106040440.

The previous prime is 221720893. The next prime is 221720969. The reversal of 221720966 is 669027122.

221720966 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221720969) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2409965 + ... + 2410056.

It is an arithmetic number, because the mean of its divisors is an integer number (43380198).

Almost surely, 2^221720966 is an apocalyptic number.

221720966 is a deficient number, since it is larger than the sum of its proper divisors (125320618).

221720966 is a wasteful number, since it uses less digits than its factorization.

221720966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4820046.

The product of its (nonzero) digits is 18144, while the sum is 35.

The square root of 221720966 is about 14890.2977136120. The cubic root of 221720966 is about 605.2510999215.

The spelling of 221720966 in words is "two hundred twenty-one million, seven hundred twenty thousand, nine hundred sixty-six".