2509661243 has 4 divisors (see below), whose sum is σ = 2511752088. Its totient is φ = 2507570400.

The previous prime is 2509661213. The next prime is 2509661251. The reversal of 2509661243 is 3421669052.

2509661243 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2509661243 - 2¹⁸ = 2509399099 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2509661197 and 2509661206.

It is not an unprimeable number, because it can be changed into a prime (2509661213) 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, 1043621 + ... + 1046022.

It is an arithmetic number, because the mean of its divisors is an integer number (627938022).

Almost surely, 2^2509661243 is an apocalyptic number.

2509661243 is a deficient number, since it is larger than the sum of its proper divisors (2090845).

2509661243 is a wasteful number, since it uses less digits than its factorization.

2509661243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2090844.

The product of its (nonzero) digits is 77760, while the sum is 38.

The square root of 2509661243 is about 50096.5192703046. The cubic root of 2509661243 is about 1358.9548708871.

The spelling of 2509661243 in words is "two billion, five hundred nine million, six hundred sixty-one thousand, two hundred forty-three".