225720 has 128 divisors (see below), whose sum is σ = 864000. Its totient is φ = 51840.

The previous prime is 225697. The next prime is 225721. The reversal of 225720 is 27522.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nialpdrome in base 12.

It is a junction number, because it is equal to n+sod(n) for n = 225693 and 225702.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (225721) by changing a digit.

225720 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11871 + ... + 11889.

It is an arithmetic number, because the mean of its divisors is an integer number (6750).

2²²⁵⁷²⁰ is an apocalyptic number.

225720 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 225720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (432000).

225720 is an abundant number, since it is smaller than the sum of its proper divisors (638280).

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

225720 is a wasteful number, since it uses less digits than its factorization.

225720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50 (or 40 counting only the distinct ones).

The product of its (nonzero) digits is 280, while the sum is 18.

The square root of 225720 is about 475.0999894759. The cubic root of 225720 is about 60.8868276978.

The spelling of 225720 in words is "two hundred twenty-five thousand, seven hundred twenty".