221321143 has 4 divisors (see below), whose sum is σ = 221450008. Its totient is φ = 221192280.

The previous prime is 221321131. The next prime is 221321159. The reversal of 221321143 is 341123122.

It is a happy number.

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-221321143 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 221321143.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221321743) 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, 61821 + ... + 65302.

It is an arithmetic number, because the mean of its divisors is an integer number (55362502).

Almost surely, 2^221321143 is an apocalyptic number.

221321143 is a deficient number, since it is larger than the sum of its proper divisors (128865).

221321143 is a wasteful number, since it uses less digits than its factorization.

221321143 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128864.

The product of its digits is 288, while the sum is 19.

The square root of 221321143 is about 14876.8660342157. The cubic root of 221321143 is about 604.8870704229.

Adding to 221321143 its reverse (341123122), we get a palindrome (562444265).

The spelling of 221321143 in words is "two hundred twenty-one million, three hundred twenty-one thousand, one hundred forty-three".