2561006111 has 4 divisors (see below), whose sum is σ = 2585870352. Its totient is φ = 2536141872.

The previous prime is 2561006081. The next prime is 2561006113. The reversal of 2561006111 is 1116001652.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2561006111 - 2¹⁰ = 2561005087 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 (2561006113) 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 3 ways as a sum of consecutive naturals, for example, 12431966 + ... + 12432171.

It is an arithmetic number, because the mean of its divisors is an integer number (646467588).

Almost surely, 2^2561006111 is an apocalyptic number.

2561006111 is a deficient number, since it is larger than the sum of its proper divisors (24864241).

2561006111 is a wasteful number, since it uses less digits than its factorization.

2561006111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24864240.

The product of its (nonzero) digits is 360, while the sum is 23.

The square root of 2561006111 is about 50606.3840933138. The cubic root of 2561006111 is about 1368.1599448701.

Adding to 2561006111 its reverse (1116001652), we get a palindrome (3677007763).

The spelling of 2561006111 in words is "two billion, five hundred sixty-one million, six thousand, one hundred eleven".