6561010733809 has 27 divisors (see below), whose sum is σ = 8055450781497. Its totient is φ = 5327461403208.

The previous prime is 6561010733743. The next prime is 6561010733821. The reversal of 6561010733809 is 9083370101656.

The square root of 6561010733809 is 2561447.

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

It is not a de Polignac number, because 6561010733809 - 2¹¹ = 6561010731761 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is not an unprimeable number, because it can be changed into a prime (6561010743809) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 340662822 + ... + 340682080.

Almost surely, 2^{6561010733809} is an apocalyptic number.

6561010733809 is the 2561447-th square number.

6561010733809 is the 1280724-th centered octagonal number.

It is an amenable number.

6561010733809 is a deficient number, since it is larger than the sum of its proper divisors (1494440047688).

6561010733809 is an frugal number, since it uses more digits than its factorization.

6561010733809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38570 (or 19285 counting only the distinct ones).

The product of its (nonzero) digits is 816480, while the sum is 49.

Multiplying 6561010733809 by its sum of digits (49), we get a square (321489525956641 = 17930129²).

6561010733809 divided by its sum of digits (49) gives a square (133898178241 = 365921²).

The spelling of 6561010733809 in words is "six trillion, five hundred sixty-one billion, ten million, seven hundred thirty-three thousand, eight hundred nine".