2585561881 has 6 divisors (see below), whose sum is σ = 3007694490. Its totient is φ = 2216195856.

The previous prime is 2585561861. The next prime is 2585561939. The reversal of 2585561881 is 1881655852.

It can be written as a sum of positive squares in only one way, i.e., 2191737856 + 393824025 = 46816^2 + 19845^2 .

It is not a de Polignac number, because 2585561881 - 2²⁷ = 2451344153 is a prime.

It is a super-2 number, since 2×2585561881² = 13370260480960516322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (49), and also a Moran number because the ratio is a prime number: 52766569 = 2585561881 / (2 + 5 + 8 + 5 + 5 + 6 + 1 + 8 + 8 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2585561861) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 26383236 + ... + 26383333.

It is an arithmetic number, because the mean of its divisors is an integer number (501282415).

Almost surely, 2^2585561881 is an apocalyptic number.

It is an amenable number.

2585561881 is a deficient number, since it is larger than the sum of its proper divisors (422132609).

2585561881 is an equidigital number, since it uses as much as digits as its factorization.

2585561881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52766583 (or 52766576 counting only the distinct ones).

The product of its digits is 768000, while the sum is 49.

The square root of 2585561881 is about 50848.4206342734. The cubic root of 2585561881 is about 1372.5188323046.

The spelling of 2585561881 in words is "two billion, five hundred eighty-five million, five hundred sixty-one thousand, eight hundred eighty-one".