2865120809 has 4 divisors (see below), whose sum is σ = 2865454080. Its totient is φ = 2864787540.

The previous prime is 2865120803. The next prime is 2865120847. The reversal of 2865120809 is 9080215682.

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, and also an emirpimes, since its reverse is a distinct semiprime: 9080215682 = 2 ⋅4540107841.

It is a cyclic number.

It is not a de Polignac number, because 2865120809 - 2⁴ = 2865120793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2865120803) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 153389 + ... + 171050.

It is an arithmetic number, because the mean of its divisors is an integer number (716363520).

Almost surely, 2^2865120809 is an apocalyptic number.

It is an amenable number.

2865120809 is a deficient number, since it is larger than the sum of its proper divisors (333271).

2865120809 is an equidigital number, since it uses as much as digits as its factorization.

2865120809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333270.

The product of its (nonzero) digits is 69120, while the sum is 41.

The square root of 2865120809 is about 53526.8232664708. The cubic root of 2865120809 is about 1420.3029190760.

The spelling of 2865120809 in words is "two billion, eight hundred sixty-five million, one hundred twenty thousand, eight hundred nine".