2561302565649 has 15 divisors (see below), whose sum is σ = 3826164855513. Its totient is φ = 1707525441324.

The previous prime is 2561302565587. The next prime is 2561302565713. The reversal of 2561302565649 is 9465652031652.

The square root of 2561302565649 is 1600407.

It is a perfect power (a square), and thus also a powerful number.

2561302565649 is a `hidden beast` number, since 2 + 5 + 6 + 1 + 30 + 2 + 565 + 6 + 49 = 666.

It is not a de Polignac number, because 2561302565649 - 2¹⁷ = 2561302434577 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 2561302565595 and 2561302565604.

It is not an unprimeable number, because it can be changed into a prime (2561302545649) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 14314752 + ... + 14492574.

Almost surely, 2^{2561302565649} is an apocalyptic number.

2561302565649 is the 1600407-th square number.

2561302565649 is the 800204-th centered octagonal number.

It is an amenable number.

2561302565649 is a deficient number, since it is larger than the sum of its proper divisors (1264862289864).

2561302565649 is an frugal number, since it uses more digits than its factorization.

2561302565649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 355658 (or 177826 counting only the distinct ones).

The product of its (nonzero) digits is 11664000, while the sum is 54.

The spelling of 2561302565649 in words is "two trillion, five hundred sixty-one billion, three hundred two million, five hundred sixty-five thousand, six hundred forty-nine".