221321225 has 12 divisors (see below), whose sum is σ = 276537360. Its totient is φ = 175702800.

The previous prime is 221321209. The next prime is 221321251. The reversal of 221321225 is 522123122.

It is not a de Polignac number, because 221321225 - 2⁴ = 221321209 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221321197 and 221321206.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 30515 + ... + 37064.

It is an arithmetic number, because the mean of its divisors is an integer number (23044780).

Almost surely, 2^221321225 is an apocalyptic number.

221321225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

221321225 is a deficient number, since it is larger than the sum of its proper divisors (55216135).

221321225 is a wasteful number, since it uses less digits than its factorization.

221321225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67720 (or 67715 counting only the distinct ones).

The product of its digits is 480, while the sum is 20.

The square root of 221321225 is about 14876.8687901722. The cubic root of 221321225 is about 604.8871451269.

Adding to 221321225 its reverse (522123122), we get a palindrome (743444347).

The spelling of 221321225 in words is "two hundred twenty-one million, three hundred twenty-one thousand, two hundred twenty-five".