225721247 has 2 divisors, whose sum is σ = 225721248. Its totient is φ = 225721246.

The previous prime is 225721219. The next prime is 225721267. The reversal of 225721247 is 742127522.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 225721247 - 2¹⁰ = 225720223 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (225721207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 112860623 + 112860624.

It is an arithmetic number, because the mean of its divisors is an integer number (112860624).

Almost surely, 2^225721247 is an apocalyptic number.

225721247 is a deficient number, since it is larger than the sum of its proper divisors (1).

225721247 is an equidigital number, since it uses as much as digits as its factorization.

225721247 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15680, while the sum is 32.

The square root of 225721247 is about 15024.0223309206. The cubic root of 225721247 is about 608.8693982161.

Adding to 225721247 its reverse (742127522), we get a palindrome (967848769).

The spelling of 225721247 in words is "two hundred twenty-five million, seven hundred twenty-one thousand, two hundred forty-seven".