225613660721 has 4 divisors (see below), whose sum is σ = 227847459444. Its totient is φ = 223379862000.

The previous prime is 225613660711. The next prime is 225613660763. The reversal of 225613660721 is 127066316522.

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 188725080625 + 36888580096 = 434425^2 + 192064^2 .

It is a cyclic number.

It is not a de Polignac number, because 225613660721 - 2¹⁰ = 225613659697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (225613660711) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1116899210 + ... + 1116899411.

It is an arithmetic number, because the mean of its divisors is an integer number (56961864861).

Almost surely, 2^225613660721 is an apocalyptic number.

It is an amenable number.

225613660721 is a deficient number, since it is larger than the sum of its proper divisors (2233798723).

225613660721 is a wasteful number, since it uses less digits than its factorization.

225613660721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2233798722.

The product of its (nonzero) digits is 181440, while the sum is 41.

The spelling of 225613660721 in words is "two hundred twenty-five billion, six hundred thirteen million, six hundred sixty thousand, seven hundred twenty-one".