221063665 has 16 divisors (see below), whose sum is σ = 290569680. Its totient is φ = 160706560.

The previous prime is 221063653. The next prime is 221063669. The reversal of 221063665 is 566360122.

It can be written as a sum of positive squares in 8 ways, for example, as 5531904 + 215531761 = 2352^2 + 14681^2 .

It is not a de Polignac number, because 221063665 - 2⁹ = 221063153 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221063669) 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, 42376 + ... + 47305.

It is an arithmetic number, because the mean of its divisors is an integer number (18160605).

Almost surely, 2^221063665 is an apocalyptic number.

It is an amenable number.

221063665 is a deficient number, since it is larger than the sum of its proper divisors (69506015).

221063665 is a wasteful number, since it uses less digits than its factorization.

221063665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89732.

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

The square root of 221063665 is about 14868.2098787985. The cubic root of 221063665 is about 604.6524105882.

The spelling of 221063665 in words is "two hundred twenty-one million, sixty-three thousand, six hundred sixty-five".