221064666 has 8 divisors (see below), whose sum is σ = 442129344. Its totient is φ = 73688220.

The previous prime is 221064653. The next prime is 221064703. The reversal of 221064666 is 666460122.

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

221064666 is an admirable number.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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, 18422050 + ... + 18422061.

It is an arithmetic number, because the mean of its divisors is an integer number (55266168).

Almost surely, 2^221064666 is an apocalyptic number.

221064666 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221064666 is a wasteful number, since it uses less digits than its factorization.

221064666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36844116.

The product of its (nonzero) digits is 20736, while the sum is 33.

The square root of 221064666 is about 14868.2435411854. The cubic root of 221064666 is about 604.6533232305.

The spelling of 221064666 in words is "two hundred twenty-one million, sixty-four thousand, six hundred sixty-six".