225521121 has 8 divisors (see below), whose sum is σ = 343651264. Its totient is φ = 128869200.

The previous prime is 225521083. The next prime is 225521123. The reversal of 225521121 is 121125522.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 225521121 - 2⁶ = 225521057 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21), and also a Moran number because the ratio is a prime number: 10739101 = 225521121 / (2 + 2 + 5 + 5 + 2 + 1 + 1 + 2 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (225521123) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5369530 + ... + 5369571.

It is an arithmetic number, because the mean of its divisors is an integer number (42956408).

Almost surely, 2^225521121 is an apocalyptic number.

225521121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

225521121 is a deficient number, since it is larger than the sum of its proper divisors (118130143).

225521121 is a wasteful number, since it uses less digits than its factorization.

225521121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10739111.

The product of its digits is 400, while the sum is 21.

The square root of 225521121 is about 15017.3606535902. The cubic root of 225521121 is about 608.6894024208.

Adding to 225521121 its reverse (121125522), we get a palindrome (346646643).

The spelling of 225521121 in words is "two hundred twenty-five million, five hundred twenty-one thousand, one hundred twenty-one".