221311312124 has 96 divisors (see below), whose sum is σ = 483087628800. Its totient is φ = 86558734080.

The previous prime is 221311312063. The next prime is 221311312223. The reversal of 221311312124 is 421213113122.

It is a self number, because there is not a number n which added to its sum of digits gives 221311312124.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6818414 + ... + 6850794.

It is an arithmetic number, because the mean of its divisors is an integer number (5032162800).

Almost surely, 2^221311312124 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221311312124, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (241543814400).

221311312124 is an abundant number, since it is smaller than the sum of its proper divisors (261776316676).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221311312124 is a wasteful number, since it uses less digits than its factorization.

221311312124 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32883 (or 32881 counting only the distinct ones).

The product of its digits is 576, while the sum is 23.

Adding to 221311312124 its reverse (421213113122), we get a palindrome (642524425246).

The spelling of 221311312124 in words is "two hundred twenty-one billion, three hundred eleven million, three hundred twelve thousand, one hundred twenty-four".