2561491730791 has 16 divisors (see below), whose sum is σ = 2968784275968. Its totient is φ = 2164543264800.

The previous prime is 2561491730789. The next prime is 2561491730797. The reversal of 2561491730791 is 1970371941652.

2561491730791 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 2561491730791 - 2¹ = 2561491730789 is a prime.

It is a super-2 number, since 2×2561491730791² (a number of 26 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2561491730797) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12232216 + ... + 12439858.

It is an arithmetic number, because the mean of its divisors is an integer number (185549017248).

Almost surely, 2^{2561491730791} is an apocalyptic number.

2561491730791 is a deficient number, since it is larger than the sum of its proper divisors (407292545177).

2561491730791 is a wasteful number, since it uses less digits than its factorization.

2561491730791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232542.

The product of its (nonzero) digits is 2857680, while the sum is 55.

The spelling of 2561491730791 in words is "two trillion, five hundred sixty-one billion, four hundred ninety-one million, seven hundred thirty thousand, seven hundred ninety-one".