2556561653 has 8 divisors (see below), whose sum is σ = 2564910936. Its totient is φ = 2548224000.

The previous prime is 2556561641. The next prime is 2556561691. The reversal of 2556561653 is 3561656552.

It can be written as a sum of positive squares in 4 ways, for example, as 132181009 + 2424380644 = 11497^2 + 49238^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2556561653 - 2¹⁴ = 2556545269 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2556561353) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 672125 + ... + 675917.

It is an arithmetic number, because the mean of its divisors is an integer number (320613867).

Almost surely, 2^2556561653 is an apocalyptic number.

It is an amenable number.

2556561653 is a deficient number, since it is larger than the sum of its proper divisors (8349283).

2556561653 is a wasteful number, since it uses less digits than its factorization.

2556561653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5815.

The product of its digits is 810000, while the sum is 44.

The square root of 2556561653 is about 50562.4529962699. The cubic root of 2556561653 is about 1367.3680359988.

The spelling of 2556561653 in words is "two billion, five hundred fifty-six million, five hundred sixty-one thousand, six hundred fifty-three".