221320225 has 12 divisors (see below), whose sum is σ = 313642624. Its totient is φ = 151762320.

The previous prime is 221320223. The next prime is 221320243. The reversal of 221320225 is 522023122.

It is not a de Polignac number, because 221320225 - 2¹ = 221320223 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221320223) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 632169 + ... + 632518.

Almost surely, 2^221320225 is an apocalyptic number.

221320225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

221320225 is a deficient number, since it is larger than the sum of its proper divisors (92322399).

221320225 is a wasteful number, since it uses less digits than its factorization.

221320225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1264704 (or 1264699 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 221320225 is about 14876.8351809113. The cubic root of 221320225 is about 604.8862341010.

Adding to 221320225 its reverse (522023122), we get a palindrome (743343347).

The spelling of 221320225 in words is "two hundred twenty-one million, three hundred twenty thousand, two hundred twenty-five".