221066651 has 4 divisors (see below), whose sum is σ = 238071792. Its totient is φ = 204061512.

The previous prime is 221066641. The next prime is 221066663. The reversal of 221066651 is 156660122.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 221066651 - 2²² = 216872347 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221066641) 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, 8502551 + ... + 8502576.

It is an arithmetic number, because the mean of its divisors is an integer number (59517948).

Almost surely, 2^221066651 is an apocalyptic number.

221066651 is a deficient number, since it is larger than the sum of its proper divisors (17005141).

221066651 is a wasteful number, since it uses less digits than its factorization.

221066651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17005140.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 221066651 is about 14868.3102940448. The cubic root of 221066651 is about 604.6551330075.

The spelling of 221066651 in words is "two hundred twenty-one million, sixty-six thousand, six hundred fifty-one".