2565448981 has 6 divisors (see below), whose sum is σ = 2570373890. Its totient is φ = 2560533456.

The previous prime is 2565448979. The next prime is 2565448993. The reversal of 2565448981 is 1898445652.

It can be written as a sum of positive squares in 3 ways, for example, as 62948356 + 2502500625 = 7934^2 + 50025^2 .

It is not a de Polignac number, because 2565448981 - 2¹ = 2565448979 is a prime.

It is a super-2 number, since 2×2565448981² = 13163056948227876722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2565448901) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 306115 + ... + 314383.

Almost surely, 2^2565448981 is an apocalyptic number.

It is an amenable number.

2565448981 is a deficient number, since it is larger than the sum of its proper divisors (4924909).

2565448981 is an frugal number, since it uses more digits than its factorization.

2565448981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9383 (or 8826 counting only the distinct ones).

The product of its digits is 2764800, while the sum is 52.

The square root of 2565448981 is about 50650.2614109740. The cubic root of 2565448981 is about 1368.9506556089.

The spelling of 2565448981 in words is "two billion, five hundred sixty-five million, four hundred forty-eight thousand, nine hundred eighty-one".