221365663 has 4 divisors (see below), whose sum is σ = 224167840. Its totient is φ = 218563488.

The previous prime is 221365657. The next prime is 221365679. The reversal of 221365663 is 366563122.

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 221365663 - 2⁵ = 221365631 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 (221365693) 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, 1400970 + ... + 1401127.

It is an arithmetic number, because the mean of its divisors is an integer number (56041960).

Almost surely, 2^221365663 is an apocalyptic number.

221365663 is a deficient number, since it is larger than the sum of its proper divisors (2802177).

221365663 is an equidigital number, since it uses as much as digits as its factorization.

221365663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2802176.

The product of its digits is 38880, while the sum is 34.

The square root of 221365663 is about 14878.3622418598. The cubic root of 221365663 is about 604.9276265224.

It can be divided in two parts, 2213 and 65663, that added together give a palindrome (67876).

The spelling of 221365663 in words is "two hundred twenty-one million, three hundred sixty-five thousand, six hundred sixty-three".