55817 has 2 divisors, whose sum is σ = 55818. Its totient is φ = 55816.

The previous prime is 55813. The next prime is 55819. The reversal of 55817 is 71855.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 55696 + 121 = 236^2 + 11^2 .

It is a cyclic number.

It is not a de Polignac number, because 55817 - 2² = 55813 is a prime.

Together with 55819, it forms a pair of twin primes.

It is a Chen prime.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (55813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27908 + 27909.

It is an arithmetic number, because the mean of its divisors is an integer number (27909).

2⁵⁵⁸¹⁷ is an apocalyptic number.

It is an amenable number.

55817 is a deficient number, since it is larger than the sum of its proper divisors (1).

55817 is an equidigital number, since it uses as much as digits as its factorization.

55817 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1400, while the sum is 26.

The square root of 55817 is about 236.2562168494. The cubic root of 55817 is about 38.2169036051.

It can be divided in two parts, 558 and 17, that added together give a palindrome (575).

The spelling of 55817 in words is "fifty-five thousand, eight hundred seventeen".