221302343424221 has 4 divisors (see below), whose sum is σ = 221302437372444. Its totient is φ = 221302249476000.

The previous prime is 221302343424203. The next prime is 221302343424307. The reversal of 221302343424221 is 122424343203122.

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

It can be written as a sum of positive squares in 2 ways, for example, as 71937623376025 + 149364720048196 = 8481605^2 + 12221486^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221302343424221 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221302343424821) 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, 43347410 + ... + 48183011.

It is an arithmetic number, because the mean of its divisors is an integer number (55325609343111).

Almost surely, 2^{221302343424221} is an apocalyptic number.

It is an amenable number.

221302343424221 is a deficient number, since it is larger than the sum of its proper divisors (93948223).

221302343424221 is an equidigital number, since it uses as much as digits as its factorization.

221302343424221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93948222.

The product of its (nonzero) digits is 110592, while the sum is 35.

Adding to 221302343424221 its reverse (122424343203122), we get a palindrome (343726686627343).

The spelling of 221302343424221 in words is "two hundred twenty-one trillion, three hundred two billion, three hundred forty-three million, four hundred twenty-four thousand, two hundred twenty-one".