221205150 has 144 divisors (see below), whose sum is σ = 623495808. Its totient is φ = 56160000.

The previous prime is 221205143. The next prime is 221205151. The reversal of 221205150 is 51502122.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221205151) 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, 1408872 + ... + 1409028.

It is an arithmetic number, because the mean of its divisors is an integer number (4329832).

Almost surely, 2^221205150 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221205150, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (311747904).

221205150 is an abundant number, since it is smaller than the sum of its proper divisors (402290658).

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

221205150 is a wasteful number, since it uses less digits than its factorization.

221205150 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 307 (or 299 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

The square root of 221205150 is about 14872.9670879754. The cubic root of 221205150 is about 604.7813794710.

Adding to 221205150 its reverse (51502122), we get a palindrome (272707272).

The spelling of 221205150 in words is "two hundred twenty-one million, two hundred five thousand, one hundred fifty".