6555820861 has 2 divisors, whose sum is σ = 6555820862. Its totient is φ = 6555820860.

The previous prime is 6555820783. The next prime is 6555820867. The reversal of 6555820861 is 1680285556.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5704931961 + 850888900 = 75531^2 + 29170^2 .

It is a cyclic number.

It is not a de Polignac number, because 6555820861 - 2¹¹ = 6555818813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6555820867) 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, 3277910430 + 3277910431.

It is an arithmetic number, because the mean of its divisors is an integer number (3277910431).

Almost surely, 2^6555820861 is an apocalyptic number.

It is an amenable number.

6555820861 is a deficient number, since it is larger than the sum of its proper divisors (1).

6555820861 is an equidigital number, since it uses as much as digits as its factorization.

6555820861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576000, while the sum is 46.

The square root of 6555820861 is about 80968.0236945425. The cubic root of 6555820861 is about 1871.5827165044.

The spelling of 6555820861 in words is "six billion, five hundred fifty-five million, eight hundred twenty thousand, eight hundred sixty-one".