221135225 has 24 divisors (see below), whose sum is σ = 287064960. Its totient is φ = 168983760.

The previous prime is 221135209. The next prime is 221135231. The reversal of 221135225 is 522531122.

221135225 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 221135225 - 2⁴ = 221135209 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a self number, because there is not a number n which added to its sum of digits gives 221135225.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 303812 + ... + 304538.

It is an arithmetic number, because the mean of its divisors is an integer number (11961040).

Almost surely, 2^221135225 is an apocalyptic number.

221135225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

221135225 is a deficient number, since it is larger than the sum of its proper divisors (65929735).

221135225 is an frugal number, since it uses more digits than its factorization.

221135225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 806 (or 755 counting only the distinct ones).

The product of its digits is 1200, while the sum is 23.

The square root of 221135225 is about 14870.6161607379. The cubic root of 221135225 is about 604.7176470869.

Adding to 221135225 its reverse (522531122), we get a palindrome (743666347).

The spelling of 221135225 in words is "two hundred twenty-one million, one hundred thirty-five thousand, two hundred twenty-five".