221225540 has 24 divisors (see below), whose sum is σ = 475379520. Its totient is φ = 86431968.

The previous prime is 221225527. The next prime is 221225549. The reversal of 221225540 is 45522122.

It is not an unprimeable number, because it can be changed into a prime (221225549) 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 7 ways as a sum of consecutive naturals, for example, 127760 + ... + 129479.

It is an arithmetic number, because the mean of its divisors is an integer number (19807480).

Almost surely, 2^221225540 is an apocalyptic number.

221225540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221225540 is an abundant number, since it is smaller than the sum of its proper divisors (254153980).

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

221225540 is a wasteful number, since it uses less digits than its factorization.

221225540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 257291 (or 257289 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 23.

The square root of 221225540 is about 14873.6525440122. The cubic root of 221225540 is about 604.7999611865.

Adding to 221225540 its reverse (45522122), we get a palindrome (266747662).

The spelling of 221225540 in words is "two hundred twenty-one million, two hundred twenty-five thousand, five hundred forty".