225356821 has 2 divisors, whose sum is σ = 225356822. Its totient is φ = 225356820.

The previous prime is 225356809. The next prime is 225356837. The reversal of 225356821 is 128653522.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 177262596 + 48094225 = 13314^2 + 6935^2 .

It is a cyclic number.

It is not a de Polignac number, because 225356821 - 2¹⁵ = 225324053 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (225356221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 112678410 + 112678411.

It is an arithmetic number, because the mean of its divisors is an integer number (112678411).

Almost surely, 2^225356821 is an apocalyptic number.

It is an amenable number.

225356821 is a deficient number, since it is larger than the sum of its proper divisors (1).

225356821 is an equidigital number, since it uses as much as digits as its factorization.

225356821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 28800, while the sum is 34.

The square root of 225356821 is about 15011.8893214678. The cubic root of 225356821 is about 608.5415493586.

The spelling of 225356821 in words is "two hundred twenty-five million, three hundred fifty-six thousand, eight hundred twenty-one".