225566820 has 144 divisors (see below), whose sum is σ = 708419712. Its totient is φ = 58060800.

The previous prime is 225566791. The next prime is 225566827. The reversal of 225566820 is 28665522.

225566820 is a `hidden beast` number, since 22 + 556 + 6 + 82 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (225566827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1168644 + ... + 1168836.

Almost surely, 2^225566820 is an apocalyptic number.

225566820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 225566820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (354209856).

225566820 is an abundant number, since it is smaller than the sum of its proper divisors (482852892).

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

225566820 is a wasteful number, since it uses less digits than its factorization.

225566820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 402 (or 397 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 36.

The square root of 225566820 is about 15018.8821155238. The cubic root of 225566820 is about 608.7305140444.

The spelling of 225566820 in words is "two hundred twenty-five million, five hundred sixty-six thousand, eight hundred twenty".