221066709 has 16 divisors (see below), whose sum is σ = 302066688. Its totient is φ = 143744112.

The previous prime is 221066693. The next prime is 221066717. The reversal of 221066709 is 907660122.

It is not a de Polignac number, because 221066709 - 2⁴ = 221066693 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221066709.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221066719) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40734 + ... + 45840.

It is an arithmetic number, because the mean of its divisors is an integer number (18879168).

Almost surely, 2^221066709 is an apocalyptic number.

It is an amenable number.

221066709 is a deficient number, since it is larger than the sum of its proper divisors (80999979).

221066709 is a wasteful number, since it uses less digits than its factorization.

221066709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5464.

The product of its (nonzero) digits is 9072, while the sum is 33.

The square root of 221066709 is about 14868.3122445017. The cubic root of 221066709 is about 604.6551858874.

The spelling of 221066709 in words is "two hundred twenty-one million, sixty-six thousand, seven hundred nine".