2551243309 has 2 divisors, whose sum is σ = 2551243310. Its totient is φ = 2551243308.

The previous prime is 2551243307. The next prime is 2551243333. The reversal of 2551243309 is 9033421552.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2255300100 + 295943209 = 47490^2 + 17203^2 .

It is a cyclic number.

It is not a de Polignac number, because 2551243309 - 2¹ = 2551243307 is a prime.

Together with 2551243307, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2551243307) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1275621654 + 1275621655.

It is an arithmetic number, because the mean of its divisors is an integer number (1275621655).

Almost surely, 2^2551243309 is an apocalyptic number.

It is an amenable number.

2551243309 is a deficient number, since it is larger than the sum of its proper divisors (1).

2551243309 is an equidigital number, since it uses as much as digits as its factorization.

2551243309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32400, while the sum is 34.

The square root of 2551243309 is about 50509.8337851155. The cubic root of 2551243309 is about 1366.4192118767.

It can be divided in two parts, 2551243 and 309, that added together give a palindrome (2551552).

The spelling of 2551243309 in words is "two billion, five hundred fifty-one million, two hundred forty-three thousand, three hundred nine".