221225771 has 4 divisors (see below), whose sum is σ = 238243152. Its totient is φ = 204208392.

The previous prime is 221225747. The next prime is 221225789. The reversal of 221225771 is 177522122.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221225771 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221225731) 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, 8508671 + ... + 8508696.

It is an arithmetic number, because the mean of its divisors is an integer number (59560788).

Almost surely, 2^221225771 is an apocalyptic number.

221225771 is a deficient number, since it is larger than the sum of its proper divisors (17017381).

221225771 is a wasteful number, since it uses less digits than its factorization.

221225771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17017380.

The product of its digits is 3920, while the sum is 29.

The square root of 221225771 is about 14873.6603094195. The cubic root of 221225771 is about 604.8001716937.

Adding to 221225771 its reverse (177522122), we get a palindrome (398747893).

It can be divided in two parts, 22 and 1225771, that multiplied together give a palindrome (26966962).

The spelling of 221225771 in words is "two hundred twenty-one million, two hundred twenty-five thousand, seven hundred seventy-one".