12440436509 has 2 divisors, whose sum is σ = 12440436510. Its totient is φ = 12440436508.

The previous prime is 12440436487. The next prime is 12440436517. The reversal of 12440436509 is 90563404421.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12419988025 + 20448484 = 111445^2 + 4522^2 .

It is a cyclic number.

It is not a de Polignac number, because 12440436509 - 2¹² = 12440432413 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12440436529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6220218254 + 6220218255.

It is an arithmetic number, because the mean of its divisors is an integer number (6220218255).

Almost surely, 2^12440436509 is an apocalyptic number.

It is an amenable number.

12440436509 is a deficient number, since it is larger than the sum of its proper divisors (1).

12440436509 is an equidigital number, since it uses as much as digits as its factorization.

12440436509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 103680, while the sum is 38.

The spelling of 12440436509 in words is "twelve billion, four hundred forty million, four hundred thirty-six thousand, five hundred nine".