556781857309 has 2 divisors, whose sum is σ = 556781857310. Its totient is φ = 556781857308.

The previous prime is 556781857279. The next prime is 556781857321. The reversal of 556781857309 is 903758187655.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 388515356100 + 168266501209 = 623310^2 + 410203^2 .

It is a cyclic number.

It is not a de Polignac number, because 556781857309 - 2¹¹ = 556781855261 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (556781857369) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 278390928654 + 278390928655.

It is an arithmetic number, because the mean of its divisors is an integer number (278390928655).

Almost surely, 2^556781857309 is an apocalyptic number.

It is an amenable number.

556781857309 is a deficient number, since it is larger than the sum of its proper divisors (1).

556781857309 is an equidigital number, since it uses as much as digits as its factorization.

556781857309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 63504000, while the sum is 64.

The spelling of 556781857309 in words is "five hundred fifty-six billion, seven hundred eighty-one million, eight hundred fifty-seven thousand, three hundred nine".