221234431213 has 8 divisors (see below), whose sum is σ = 223441933176. Its totient is φ = 219027264000.

The previous prime is 221234431177. The next prime is 221234431219. The reversal of 221234431213 is 312134432122.

It can be written as a sum of positive squares in 4 ways, for example, as 5825200329 + 215409230884 = 76323^2 + 464122^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 221234431213 - 2⁹ = 221234430701 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 (221234431219) 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, 1369945 + ... + 1522897.

It is an arithmetic number, because the mean of its divisors is an integer number (27930241647).

Almost surely, 2^221234431213 is an apocalyptic number.

It is an amenable number.

221234431213 is a deficient number, since it is larger than the sum of its proper divisors (2207501963).

221234431213 is a wasteful number, since it uses less digits than its factorization.

221234431213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167375.

The product of its digits is 6912, while the sum is 28.

Adding to 221234431213 its reverse (312134432122), we get a palindrome (533368863335).

Subtracting 221234431213 from its reverse (312134432122), we obtain a palindrome (90900000909).

The spelling of 221234431213 in words is "two hundred twenty-one billion, two hundred thirty-four million, four hundred thirty-one thousand, two hundred thirteen".