40440864809 has 2 divisors, whose sum is σ = 40440864810. Its totient is φ = 40440864808.

The previous prime is 40440864803. The next prime is 40440864859. The reversal of 40440864809 is 90846804404.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27569281600 + 12871583209 = 166040^2 + 113453^2 .

It is a cyclic number.

It is not a de Polignac number, because 40440864809 - 2²⁰ = 40439816233 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (40440864803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20220432404 + 20220432405.

It is an arithmetic number, because the mean of its divisors is an integer number (20220432405).

Almost surely, 2^40440864809 is an apocalyptic number.

It is an amenable number.

40440864809 is a deficient number, since it is larger than the sum of its proper divisors (1).

40440864809 is an equidigital number, since it uses as much as digits as its factorization.

40440864809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 884736, while the sum is 47.

The spelling of 40440864809 in words is "forty billion, four hundred forty million, eight hundred sixty-four thousand, eight hundred nine".