555656561 has 2 divisors, whose sum is σ = 555656562. Its totient is φ = 555656560.

The previous prime is 555656557. The next prime is 555656567. The reversal of 555656561 is 165656555.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 546390625 + 9265936 = 23375^2 + 3044^2 .

It is a cyclic number.

It is not a de Polignac number, because 555656561 - 2² = 555656557 is a prime.

It is not a weakly prime, because it can be changed into another prime (555656567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 277828280 + 277828281.

It is an arithmetic number, because the mean of its divisors is an integer number (277828281).

Almost surely, 2^555656561 is an apocalyptic number.

It is an amenable number.

555656561 is a deficient number, since it is larger than the sum of its proper divisors (1).

555656561 is an equidigital number, since it uses as much as digits as its factorization.

555656561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 675000, while the sum is 44.

The square root of 555656561 is about 23572.3685912129. The cubic root of 555656561 is about 822.1205085939.

It can be divided in two parts, 55565 and 6561, that added together give a palindrome (62126).

The spelling of 555656561 in words is "five hundred fifty-five million, six hundred fifty-six thousand, five hundred sixty-one".