225666513665 has 8 divisors (see below), whose sum is σ = 274509403368. Its totient is φ = 178060152960.

The previous prime is 225666513661. The next prime is 225666513731. The reversal of 225666513665 is 566315666522.

It can be written as a sum of positive squares in 4 ways, for example, as 71006793841 + 154659719824 = 266471^2 + 393268^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 225666513665 - 2² = 225666513661 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (225666513661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 309131846 + ... + 309132575.

It is an arithmetic number, because the mean of its divisors is an integer number (34313675421).

Almost surely, 2^225666513665 is an apocalyptic number.

It is an amenable number.

225666513665 is a deficient number, since it is larger than the sum of its proper divisors (48842889703).

225666513665 is an equidigital number, since it uses as much as digits as its factorization.

225666513665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 618264499.

The product of its digits is 11664000, while the sum is 53.

The spelling of 225666513665 in words is "two hundred twenty-five billion, six hundred sixty-six million, five hundred thirteen thousand, six hundred sixty-five".