221442312 has 128 divisors (see below), whose sum is σ = 698261760. Its totient is φ = 56954880.

The previous prime is 221442311. The next prime is 221442317. The reversal of 221442312 is 213244122.

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

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (221442311) 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, 88308 + ... + 90780.

It is an arithmetic number, because the mean of its divisors is an integer number (5455170).

Almost surely, 2^221442312 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 221442312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (349130880).

221442312 is an abundant number, since it is smaller than the sum of its proper divisors (476819448).

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

221442312 is a wasteful number, since it uses less digits than its factorization.

221442312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2543 (or 2539 counting only the distinct ones).

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

The square root of 221442312 is about 14880.9378736691. The cubic root of 221442312 is about 604.9974382334.

Adding to 221442312 its reverse (213244122), we get a palindrome (434686434).

The spelling of 221442312 in words is "two hundred twenty-one million, four hundred forty-two thousand, three hundred twelve".