2561335785 has 48 divisors (see below), whose sum is σ = 4607336448. Its totient is φ = 1314921600.

The previous prime is 2561335783. The next prime is 2561335801. The reversal of 2561335785 is 5875331652.

2561335785 is a `hidden beast` number, since 2 + 561 + 3 + 3 + 5 + 7 + 85 = 666.

2561335785 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 2561335785 - 2¹ = 2561335783 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 2561335785.

It is not an unprimeable number, because it can be changed into a prime (2561335783) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 261639 + ... + 271251.

It is an arithmetic number, because the mean of its divisors is an integer number (95986176).

Almost surely, 2^2561335785 is an apocalyptic number.

It is an amenable number.

2561335785 is a deficient number, since it is larger than the sum of its proper divisors (2046000663).

2561335785 is a wasteful number, since it uses less digits than its factorization.

2561335785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9846 (or 9843 counting only the distinct ones).

The product of its digits is 756000, while the sum is 45.

The square root of 2561335785 is about 50609.6412257586. The cubic root of 2561335785 is about 1368.2186493258.

The spelling of 2561335785 in words is "two billion, five hundred sixty-one million, three hundred thirty-five thousand, seven hundred eighty-five".