225888821 has 4 divisors (see below), whose sum is σ = 225924492. Its totient is φ = 225853152.

The previous prime is 225888797. The next prime is 225888833. The reversal of 225888821 is 128888522.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 79744900 + 146143921 = 8930^2 + 12089^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-225888821 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (225888841) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5486 + ... + 21951.

It is an arithmetic number, because the mean of its divisors is an integer number (56481123).

Almost surely, 2^225888821 is an apocalyptic number.

It is an amenable number.

225888821 is a deficient number, since it is larger than the sum of its proper divisors (35671).

225888821 is an equidigital number, since it uses as much as digits as its factorization.

225888821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35670.

The product of its digits is 163840, while the sum is 44.

The square root of 225888821 is about 15029.5981649544. The cubic root of 225888821 is about 609.0200345184.

The spelling of 225888821 in words is "two hundred twenty-five million, eight hundred eighty-eight thousand, eight hundred twenty-one".