6561768944025 has 27 divisors (see below), whose sum is σ = 11752926086109. Its totient is φ = 3499589610720.

The previous prime is 6561768944011. The next prime is 6561768944053. The reversal of 6561768944025 is 5204498671656.

The square root of 6561768944025 is 2561595.

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

6561768944025 is a `hidden beast` number, since 6 + 5 + 617 + 6 + 8 + 9 + 4 + 4 + 0 + 2 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 230466244761 + 6331302699264 = 480069^2 + 2516208^2 .

It is not a de Polignac number, because 6561768944025 - 2¹⁷ = 6561768812953 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 38338539 + ... + 38509311.

Almost surely, 2^{6561768944025} is an apocalyptic number.

6561768944025 is the 2561595-th square number.

6561768944025 is the 1280798-th centered octagonal number.

It is an amenable number.

6561768944025 is a deficient number, since it is larger than the sum of its proper divisors (5191157142084).

6561768944025 is an frugal number, since it uses more digits than its factorization.

6561768944025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 341562 (or 170781 counting only the distinct ones).

The product of its (nonzero) digits is 87091200, while the sum is 63.

The spelling of 6561768944025 in words is "six trillion, five hundred sixty-one billion, seven hundred sixty-eight million, nine hundred forty-four thousand, twenty-five".