555691 has 2 divisors, whose sum is σ = 555692. Its totient is φ = 555690.

The previous prime is 555683. The next prime is 555697. The reversal of 555691 is 196555.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 555691 - 2³ = 555683 is a prime.

It is not a weakly prime, because it can be changed into another prime (555697) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 277845 + 277846.

It is an arithmetic number, because the mean of its divisors is an integer number (277846).

2⁵⁵⁵⁶⁹¹ is an apocalyptic number.

555691 is a deficient number, since it is larger than the sum of its proper divisors (1).

555691 is an equidigital number, since it uses as much as digits as its factorization.

555691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6750, while the sum is 31.

The square root of 555691 is about 745.4468458582. The cubic root of 555691 is about 82.2137492960.

It can be divided in two parts, 5 and 55691, that added together give a square (55696 = 236²).

The spelling of 555691 in words is "five hundred fifty-five thousand, six hundred ninety-one".