2399309081 has 16 divisors (see below), whose sum is σ = 2623395600. Its totient is φ = 2181070848.

The previous prime is 2399309071. The next prime is 2399309117. The reversal of 2399309081 is 1809039932.

It can be written as a sum of positive squares in 8 ways, for example, as 363855625 + 2035453456 = 19075^2 + 45116^2 .

It is a cyclic number.

It is not a de Polignac number, because 2399309081 - 2²⁶ = 2332200217 is a prime.

It is a super-2 number, since 2×2399309081² = 11513368132338129122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2399309021) 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 15 ways as a sum of consecutive naturals, for example, 293315 + ... + 301383.

It is an arithmetic number, because the mean of its divisors is an integer number (163962225).

Almost surely, 2^2399309081 is an apocalyptic number.

It is an amenable number.

2399309081 is a deficient number, since it is larger than the sum of its proper divisors (224086519).

2399309081 is a wasteful number, since it uses less digits than its factorization.

2399309081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8428.

The product of its (nonzero) digits is 104976, while the sum is 44.

The square root of 2399309081 is about 48982.7426855622. The cubic root of 2399309081 is about 1338.7374089600.

The spelling of 2399309081 in words is "two billion, three hundred ninety-nine million, three hundred nine thousand, eighty-one".