223021221 has 16 divisors (see below), whose sum is σ = 313371840. Its totient is φ = 140693760.

The previous prime is 223021217. The next prime is 223021241. The reversal of 223021221 is 122120322.

It is a happy number.

It is not a de Polignac number, because 223021221 - 2² = 223021217 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 223021221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (223021241) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 65661 + ... + 68973.

It is an arithmetic number, because the mean of its divisors is an integer number (19585740).

Almost surely, 2^223021221 is an apocalyptic number.

It is an amenable number.

223021221 is a deficient number, since it is larger than the sum of its proper divisors (90350619).

223021221 is a wasteful number, since it uses less digits than its factorization.

223021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4516.

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 223021221 is about 14933.8950377991. The cubic root of 223021221 is about 606.4319345415.

Adding to 223021221 its reverse (122120322), we get a palindrome (345141543).

The spelling of 223021221 in words is "two hundred twenty-three million, twenty-one thousand, two hundred twenty-one".