555661111 has 2 divisors, whose sum is σ = 555661112. Its totient is φ = 555661110.

The previous prime is 555661109. The next prime is 555661157. The reversal of 555661111 is 111166555.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 555661111 - 2¹ = 555661109 is a prime.

Together with 555661109, it forms a pair of twin primes.

It is a zygodrome in base 10.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (555662111) 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, 277830555 + 277830556.

It is an arithmetic number, because the mean of its divisors is an integer number (277830556).

Almost surely, 2^555661111 is an apocalyptic number.

555661111 is a deficient number, since it is larger than the sum of its proper divisors (1).

555661111 is an equidigital number, since it uses as much as digits as its factorization.

555661111 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4500, while the sum is 31.

The square root of 555661111 is about 23572.4651023180. The cubic root of 555661111 is about 822.1227525687.

The spelling of 555661111 in words is "five hundred fifty-five million, six hundred sixty-one thousand, one hundred eleven".