2543509 has 2 divisors, whose sum is σ = 2543510. Its totient is φ = 2543508.

The previous prime is 2543507. The next prime is 2543537. The reversal of 2543509 is 9053452.

It is an a-pointer prime, because the next prime (2543537) can be obtained adding 2543509 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2241009 + 302500 = 1497^2 + 550^2 .

It is a cyclic number.

It is not a de Polignac number, because 2543509 - 2¹ = 2543507 is a prime.

Together with 2543507, 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 (2543507) 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 as a sum of consecutive naturals, namely, 1271754 + 1271755.

It is an arithmetic number, because the mean of its divisors is an integer number (1271755).

2^2543509 is an apocalyptic number.

It is an amenable number.

2543509 is a deficient number, since it is larger than the sum of its proper divisors (1).

2543509 is an equidigital number, since it uses as much as digits as its factorization.

2543509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5400, while the sum is 28.

The square root of 2543509 is about 1594.8382363111. The cubic root of 2543509 is about 136.5037009198.

It can be divided in two parts, 25 and 43509, that added together give a palindrome (43534).

The spelling of 2543509 in words is "two million, five hundred forty-three thousand, five hundred nine".