2581681911 has 4 divisors (see below), whose sum is σ = 3442242552. Its totient is φ = 1721121272.

The previous prime is 2581681901. The next prime is 2581681937. The reversal of 2581681911 is 1191861852.

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 2581681911 - 2⁷ = 2581681783 is a prime.

It is a super-2 number, since 2×2581681911² = 13330162979169223842, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2581681901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 430280316 + ... + 430280321.

It is an arithmetic number, because the mean of its divisors is an integer number (860560638).

Almost surely, 2^2581681911 is an apocalyptic number.

2581681911 is a deficient number, since it is larger than the sum of its proper divisors (860560641).

2581681911 is an equidigital number, since it uses as much as digits as its factorization.

2581681911 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 860560640.

The product of its digits is 34560, while the sum is 42.

The square root of 2581681911 is about 50810.2539946417. The cubic root of 2581681911 is about 1371.8319412606.

The spelling of 2581681911 in words is "two billion, five hundred eighty-one million, six hundred eighty-one thousand, nine hundred eleven".