2585661661 has 4 divisors (see below), whose sum is σ = 2820721824. Its totient is φ = 2350601500.

The previous prime is 2585661653. The next prime is 2585661697. The reversal of 2585661661 is 1661665852.

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 not a de Polignac number, because 2585661661 - 2³ = 2585661653 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 (2585661601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 117530065 + ... + 117530086.

It is an arithmetic number, because the mean of its divisors is an integer number (705180456).

Almost surely, 2^2585661661 is an apocalyptic number.

It is an amenable number.

2585661661 is a deficient number, since it is larger than the sum of its proper divisors (235060163).

2585661661 is a wasteful number, since it uses less digits than its factorization.

2585661661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 235060162.

The product of its digits is 518400, while the sum is 46.

The square root of 2585661661 is about 50849.4017762255. The cubic root of 2585661661 is about 1372.5364878052.

The spelling of 2585661661 in words is "two billion, five hundred eighty-five million, six hundred sixty-one thousand, six hundred sixty-one".