221345663 has 12 divisors (see below), whose sum is σ = 278055120. Its totient is φ = 172476480.

The previous prime is 221345659. The next prime is 221345669. The reversal of 221345663 is 366543122.

It is not a de Polignac number, because 221345663 - 2² = 221345659 is a prime.

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221345669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 129818 + ... + 131511.

It is an arithmetic number, because the mean of its divisors is an integer number (23171260).

Almost surely, 2^221345663 is an apocalyptic number.

221345663 is a deficient number, since it is larger than the sum of its proper divisors (56709457).

221345663 is a wasteful number, since it uses less digits than its factorization.

221345663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 261358 (or 261347 counting only the distinct ones).

The product of its digits is 25920, while the sum is 32.

The square root of 221345663 is about 14877.6901096911. The cubic root of 221345663 is about 604.9094079231.

Adding to 221345663 its reverse (366543122), we get a palindrome (587888785).

The spelling of 221345663 in words is "two hundred twenty-one million, three hundred forty-five thousand, six hundred sixty-three".