221224143 has 32 divisors (see below), whose sum is σ = 356769792. Its totient is φ = 119196000.

The previous prime is 221224139. The next prime is 221224169. The reversal of 221224143 is 341422122.

It is not a de Polignac number, because 221224143 - 2² = 221224139 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221224123) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 31068 + ... + 37518.

It is an arithmetic number, because the mean of its divisors is an integer number (11149056).

Almost surely, 2^221224143 is an apocalyptic number.

221224143 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

221224143 is a deficient number, since it is larger than the sum of its proper divisors (135545649).

221224143 is a wasteful number, since it uses less digits than its factorization.

221224143 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6555.

The product of its digits is 768, while the sum is 21.

The square root of 221224143 is about 14873.6055817008. The cubic root of 221224143 is about 604.7986881157.

Adding to 221224143 its reverse (341422122), we get a palindrome (562646265).

The spelling of 221224143 in words is "two hundred twenty-one million, two hundred twenty-four thousand, one hundred forty-three".