2561606785 has 16 divisors (see below), whose sum is σ = 3088108800. Its totient is φ = 2039855616.

The previous prime is 2561606753. The next prime is 2561606813. The reversal of 2561606785 is 5876061652.

It is a cyclic number.

It is not a de Polignac number, because 2561606785 - 2⁵ = 2561606753 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1355121 + ... + 1357009.

It is an arithmetic number, because the mean of its divisors is an integer number (193006800).

Almost surely, 2^2561606785 is an apocalyptic number.

It is an amenable number.

2561606785 is a deficient number, since it is larger than the sum of its proper divisors (526502015).

2561606785 is a wasteful number, since it uses less digits than its factorization.

2561606785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3000.

The product of its (nonzero) digits is 604800, while the sum is 46.

The square root of 2561606785 is about 50612.3185104180. The cubic root of 2561606785 is about 1368.2669020357.

The spelling of 2561606785 in words is "two billion, five hundred sixty-one million, six hundred six thousand, seven hundred eighty-five".