55691 has 2 divisors, whose sum is σ = 55692. Its totient is φ = 55690.

The previous prime is 55681. The next prime is 55697. The reversal of 55691 is 19655.

55691 is nontrivially palindromic in base 9.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 55691 - 2¹⁰ = 54667 is a prime.

It is a plaindrome in base 15.

It is a self number, because there is not a number n which added to its sum of digits gives 55691.

It is not a weakly prime, because it can be changed into another prime (55697) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27845 + 27846.

It is an arithmetic number, because the mean of its divisors is an integer number (27846).

2⁵⁵⁶⁹¹ is an apocalyptic number.

55691 is a deficient number, since it is larger than the sum of its proper divisors (1).

55691 is an equidigital number, since it uses as much as digits as its factorization.

55691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1350, while the sum is 26.

The square root of 55691 is about 235.9894065419. The cubic root of 55691 is about 38.1881252894.

The spelling of 55691 in words is "fifty-five thousand, six hundred ninety-one".