1664231560225 has 18 divisors (see below), whose sum is σ = 2234600157426. Its totient is φ = 1228970995200.

The previous prime is 1664231560223. The next prime is 1664231560237. The reversal of 1664231560225 is 5220651324661.

It can be written as a sum of positive squares in 9 ways, for example, as 1195433902881 + 468797657344 = 1093359^2 + 684688^2 .

It is not a de Polignac number, because 1664231560225 - 2¹ = 1664231560223 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1664231560223) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 196946256 + ... + 196954705.

Almost surely, 2^{1664231560225} is an apocalyptic number.

It is an amenable number.

1664231560225 is a deficient number, since it is larger than the sum of its proper divisors (570368597201).

1664231560225 is a wasteful number, since it uses less digits than its factorization.

1664231560225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 393900997 (or 393900979 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 43.

Adding to 1664231560225 its reverse (5220651324661), we get a palindrome (6884882884886).

The spelling of 1664231560225 in words is "one trillion, six hundred sixty-four billion, two hundred thirty-one million, five hundred sixty thousand, two hundred twenty-five".