556756861 has 2 divisors, whose sum is σ = 556756862. Its totient is φ = 556756860.

The previous prime is 556756859. The next prime is 556756897. The reversal of 556756861 is 168657655.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 544288900 + 12467961 = 23330^2 + 3531^2 .

It is a cyclic number.

It is not a de Polignac number, because 556756861 - 2¹ = 556756859 is a prime.

Together with 556756859, 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 (556756831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 278378430 + 278378431.

It is an arithmetic number, because the mean of its divisors is an integer number (278378431).

Almost surely, 2^556756861 is an apocalyptic number.

It is an amenable number.

556756861 is a deficient number, since it is larger than the sum of its proper divisors (1).

556756861 is an equidigital number, since it uses as much as digits as its factorization.

556756861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1512000, while the sum is 49.

The square root of 556756861 is about 23595.6958151270. The cubic root of 556756861 is about 822.6627996651.

The spelling of 556756861 in words is "five hundred fifty-six million, seven hundred fifty-six thousand, eight hundred sixty-one".