225245021 has 4 divisors (see below), whose sum is σ = 230738844. Its totient is φ = 219751200.

The previous prime is 225244993. The next prime is 225245029. The reversal of 225245021 is 120542522.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 116856100 + 108388921 = 10810^2 + 10411^2 .

It is a cyclic number.

It is not a de Polignac number, because 225245021 - 2²² = 221050717 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (225245029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2746850 + ... + 2746931.

It is an arithmetic number, because the mean of its divisors is an integer number (57684711).

Almost surely, 2^225245021 is an apocalyptic number.

It is an amenable number.

225245021 is a deficient number, since it is larger than the sum of its proper divisors (5493823).

225245021 is an equidigital number, since it uses as much as digits as its factorization.

225245021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5493822.

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

The square root of 225245021 is about 15008.1651443473. The cubic root of 225245021 is about 608.4408997920.

Adding to 225245021 its reverse (120542522), we get a palindrome (345787543).

The spelling of 225245021 in words is "two hundred twenty-five million, two hundred forty-five thousand, twenty-one".