2581606609 has 4 divisors (see below), whose sum is σ = 2641644016. Its totient is φ = 2521569204.

The previous prime is 2581606583. The next prime is 2581606613. The reversal of 2581606609 is 9066061852.

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 2581606609 - 2¹¹ = 2581604561 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (43), and also a Moran number because the ratio is a prime number: 60037363 = 2581606609 / (2 + 5 + 8 + 1 + 6 + 0 + 6 + 6 + 0 + 9).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2581606619) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30018639 + ... + 30018724.

It is an arithmetic number, because the mean of its divisors is an integer number (660411004).

Almost surely, 2^2581606609 is an apocalyptic number.

It is an amenable number.

2581606609 is a deficient number, since it is larger than the sum of its proper divisors (60037407).

2581606609 is an equidigital number, since it uses as much as digits as its factorization.

2581606609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60037406.

The product of its (nonzero) digits is 155520, while the sum is 43.

The square root of 2581606609 is about 50809.5129773943. The cubic root of 2581606609 is about 1371.8186033544.

The spelling of 2581606609 in words is "two billion, five hundred eighty-one million, six hundred six thousand, six hundred nine".