2561243563 has 8 divisors (see below), whose sum is σ = 2667517920. Its totient is φ = 2456919360.

The previous prime is 2561243561. The next prime is 2561243593. The reversal of 2561243563 is 3653421652.

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 2561243563 - 2¹ = 2561243561 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2561243561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 484858 + ... + 490111.

It is an arithmetic number, because the mean of its divisors is an integer number (333439740).

Almost surely, 2^2561243563 is an apocalyptic number.

2561243563 is a deficient number, since it is larger than the sum of its proper divisors (106274357).

2561243563 is an equidigital number, since it uses as much as digits as its factorization.

2561243563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 975077.

The product of its digits is 129600, while the sum is 37.

The square root of 2561243563 is about 50608.7301065735. The cubic root of 2561243563 is about 1368.2022280278.

The spelling of 2561243563 in words is "two billion, five hundred sixty-one million, two hundred forty-three thousand, five hundred sixty-three".