225840 has 40 divisors (see below), whose sum is σ = 700848. Its totient is φ = 60160.

The previous prime is 225839. The next prime is 225859. The reversal of 225840 is 48522.

225840 = 68² + 69² + ... + 99².

It is a tau number, because it is divible by the number of its divisors (40).

It is a nialpdrome in base 12.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 231 + ... + 710.

2²²⁵⁸⁴⁰ is an apocalyptic number.

225840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

225840 is an abundant number, since it is smaller than the sum of its proper divisors (475008).

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

225840 is a wasteful number, since it uses less digits than its factorization.

225840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 957 (or 951 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 21.

The square root of 225840 is about 475.2262619006. The cubic root of 225840 is about 60.8976155839.

The spelling of 225840 in words is "two hundred twenty-five thousand, eight hundred forty".