440991809 has 2 divisors, whose sum is σ = 440991810. Its totient is φ = 440991808.

The previous prime is 440991799. The next prime is 440991821. The reversal of 440991809 is 908199044.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 285441025 + 155550784 = 16895^2 + 12472^2 .

It is a cyclic number.

It is not a de Polignac number, because 440991809 - 2¹² = 440987713 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 440991809.

It is not a weakly prime, because it can be changed into another prime (440991869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 220495904 + 220495905.

It is an arithmetic number, because the mean of its divisors is an integer number (220495905).

Almost surely, 2^440991809 is an apocalyptic number.

It is an amenable number.

440991809 is a deficient number, since it is larger than the sum of its proper divisors (1).

440991809 is an equidigital number, since it uses as much as digits as its factorization.

440991809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 93312, while the sum is 44.

The square root of 440991809 is about 20999.8049752849. The cubic root of 440991809 is about 761.1615485159.

The spelling of 440991809 in words is "four hundred forty million, nine hundred ninety-one thousand, eight hundred nine".