2656081809 has 6 divisors (see below), whose sum is σ = 3836562626. Its totient is φ = 1770721200.

The previous prime is 2656081781. The next prime is 2656081849. The reversal of 2656081809 is 9081806562.

2656081809 is a `hidden beast` number, since 2 + 6 + 560 + 8 + 1 + 80 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 2113424784 + 542657025 = 45972^2 + 23295^2 .

It is not a de Polignac number, because 2656081809 - 2¹¹ = 2656079761 is a prime.

It is a super-2 number, since 2×2656081809² = 14109541152201424962, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2656081849) 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, 147560092 + ... + 147560109.

Almost surely, 2^2656081809 is an apocalyptic number.

It is an amenable number.

2656081809 is a deficient number, since it is larger than the sum of its proper divisors (1180480817).

2656081809 is a wasteful number, since it uses less digits than its factorization.

2656081809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 295120207 (or 295120204 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 45.

The square root of 2656081809 is about 51537.1886020183. The cubic root of 2656081809 is about 1384.8853331195.

The spelling of 2656081809 in words is "two billion, six hundred fifty-six million, eighty-one thousand, eight hundred nine".