305666221 has 8 divisors (see below), whose sum is σ = 349504704. Its totient is φ = 261870720.

The previous prime is 305666203. The next prime is 305666269. The reversal of 305666221 is 122666503.

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

It is a cyclic number.

It is not a de Polignac number, because 305666221 - 2⁷ = 305666093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (305666321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6306 + ... + 25516.

It is an arithmetic number, because the mean of its divisors is an integer number (43688088).

Almost surely, 2^305666221 is an apocalyptic number.

It is an amenable number.

305666221 is a deficient number, since it is larger than the sum of its proper divisors (43838483).

305666221 is a wasteful number, since it uses less digits than its factorization.

305666221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21491.

The product of its (nonzero) digits is 12960, while the sum is 31.

The square root of 305666221 is about 17483.3126437755. The cubic root of 305666221 is about 673.6213073720.

The spelling of 305666221 in words is "three hundred five million, six hundred sixty-six thousand, two hundred twenty-one".