221563 has 4 divisors (see below), whose sum is σ = 223200. Its totient is φ = 219928.

The previous prime is 221549. The next prime is 221567. The reversal of 221563 is 365122.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 365122 = 2 ⋅182561.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221563 is a prime.

It is a super-3 number, since 3×221563³ = 32629691333701641, which contains 333 as substring.

It is a Duffinian number.

221563 is a lucky number.

It is a plaindrome in base 15.

It is a self number, because there is not a number n which added to its sum of digits gives 221563.

It is not an unprimeable number, because it can be changed into a prime (221567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 595 + ... + 892.

It is an arithmetic number, because the mean of its divisors is an integer number (55800).

2²²¹⁵⁶³ is an apocalyptic number.

221563 is the 298-th heptagonal number.

221563 is a deficient number, since it is larger than the sum of its proper divisors (1637).

221563 is a wasteful number, since it uses less digits than its factorization.

221563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1636.

The product of its digits is 360, while the sum is 19.

The square root of 221563 is about 470.7047907128. The cubic root of 221563 is about 60.5107327907.

Adding to 221563 its reverse (365122), we get a palindrome (586685).

It can be divided in two parts, 2215 and 63, that added together give a triangular number (2278 = T₆₇).

The spelling of 221563 in words is "two hundred twenty-one thousand, five hundred sixty-three".