225799821 has 12 divisors (see below), whose sum is σ = 351244348. Its totient is φ = 138953664.

The previous prime is 225799799. The next prime is 225799841. The reversal of 225799821 is 128997522.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 73770921 + 152028900 = 8589^2 + 12330^2 .

It is not a de Polignac number, because 225799821 - 2⁹ = 225799309 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (225799841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 964840 + ... + 965073.

Almost surely, 2^225799821 is an apocalyptic number.

It is an amenable number.

225799821 is a deficient number, since it is larger than the sum of its proper divisors (125444527).

225799821 is a wasteful number, since it uses less digits than its factorization.

225799821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1929932 (or 1929929 counting only the distinct ones).

The product of its digits is 181440, while the sum is 45.

The square root of 225799821 is about 15026.6370489208. The cubic root of 225799821 is about 608.9400395560.

It can be divided in two parts, 22579 and 9821, that added together give a square (32400 = 180²).

The spelling of 225799821 in words is "two hundred twenty-five million, seven hundred ninety-nine thousand, eight hundred twenty-one".