2081565509 has 8 divisors (see below), whose sum is σ = 2154666360. Its totient is φ = 2008552896.

The previous prime is 2081565491. The next prime is 2081565511. The reversal of 2081565509 is 9055651802.

It can be written as a sum of positive squares in 4 ways, for example, as 309408100 + 1772157409 = 17590^2 + 42097^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2081565509 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2081565569) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27899 + ... + 70295.

It is an arithmetic number, because the mean of its divisors is an integer number (269333295).

Almost surely, 2^2081565509 is an apocalyptic number.

2081565509 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

2081565509 is a deficient number, since it is larger than the sum of its proper divisors (73100851).

2081565509 is a wasteful number, since it uses less digits than its factorization.

2081565509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44119.

The product of its (nonzero) digits is 108000, while the sum is 41.

The square root of 2081565509 is about 45624.1768035326. The cubic root of 2081565509 is about 1276.8210316368.

The spelling of 2081565509 in words is "two billion, eighty-one million, five hundred sixty-five thousand, five hundred nine".