2561115329 has 4 divisors (see below), whose sum is σ = 2566599984. Its totient is φ = 2555630676.

The previous prime is 2561115311. The next prime is 2561115341. The reversal of 2561115329 is 9235111652.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2561115329 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2561117329) 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 3 ways as a sum of consecutive naturals, for example, 2741627 + ... + 2742560.

It is an arithmetic number, because the mean of its divisors is an integer number (641649996).

Almost surely, 2^2561115329 is an apocalyptic number.

It is an amenable number.

2561115329 is a deficient number, since it is larger than the sum of its proper divisors (5484655).

2561115329 is an equidigital number, since it uses as much as digits as its factorization.

2561115329 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5484654.

The product of its digits is 16200, while the sum is 35.

The square root of 2561115329 is about 50607.4631749113. The cubic root of 2561115329 is about 1368.1793936808.

The spelling of 2561115329 in words is "two billion, five hundred sixty-one million, one hundred fifteen thousand, three hundred twenty-nine".