221445450 has 144 divisors (see below), whose sum is σ = 626745600. Its totient is φ = 55977600.

The previous prime is 221445391. The next prime is 221445457. The reversal of 221445450 is 54544122.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (221445457) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 926431 + ... + 926669.

It is an arithmetic number, because the mean of its divisors is an integer number (4352400).

Almost surely, 2^221445450 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221445450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (313372800).

221445450 is an abundant number, since it is smaller than the sum of its proper divisors (405300150).

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

221445450 is a wasteful number, since it uses less digits than its factorization.

221445450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 357 (or 349 counting only the distinct ones).

The product of its (nonzero) digits is 6400, while the sum is 27.

The square root of 221445450 is about 14881.0433101984. The cubic root of 221445450 is about 605.0002959724. Note that the first 3 decimals are identical.

Adding to 221445450 its reverse (54544122), we get a palindrome (275989572).

The spelling of 221445450 in words is "two hundred twenty-one million, four hundred forty-five thousand, four hundred fifty".