221241221 has 8 divisors (see below), whose sum is σ = 223104000. Its totient is φ = 219386160.

The previous prime is 221241211. The next prime is 221241227. The reversal of 221241221 is 122142122.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221241221 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 221241221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221241227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 65000 + ... + 68318.

It is an arithmetic number, because the mean of its divisors is an integer number (27888000).

Almost surely, 2^221241221 is an apocalyptic number.

It is an amenable number.

221241221 is a deficient number, since it is larger than the sum of its proper divisors (1862779).

221241221 is a wasteful number, since it uses less digits than its factorization.

221241221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3859.

The product of its digits is 128, while the sum is 17.

The square root of 221241221 is about 14874.1796748594. The cubic root of 221241221 is about 604.8142507423.

Adding to 221241221 its reverse (122142122), we get a palindrome (343383343).

Subtracting from 221241221 its reverse (122142122), we obtain a palindrome (99099099).

The spelling of 221241221 in words is "two hundred twenty-one million, two hundred forty-one thousand, two hundred twenty-one".