55665 has 12 divisors (see below), whose sum is σ = 96564. Its totient is φ = 29664.

The previous prime is 55663. The next prime is 55667. The reversal of 55665 is 56655.

It is an interprime number because it is at equal distance from previous prime (55663) and next prime (55667).

It can be written as a sum of positive squares in 2 ways, for example, as 31329 + 24336 = 177^2 + 156^2 .

It is not a de Polignac number, because 55665 - 2¹ = 55663 is a prime.

55665 is a lucky number.

It is a nialpdrome in base 9 and base 16.

It is not an unprimeable number, because it can be changed into a prime (55661) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 574 + ... + 663.

It is an arithmetic number, because the mean of its divisors is an integer number (8047).

2⁵⁵⁶⁶⁵ is an apocalyptic number.

It is an amenable number.

55665 is a deficient number, since it is larger than the sum of its proper divisors (40899).

55665 is a wasteful number, since it uses less digits than its factorization.

55665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1248 (or 1245 counting only the distinct ones).

The product of its digits is 4500, while the sum is 27.

The square root of 55665 is about 235.9343128924. The cubic root of 55665 is about 38.1821815055.

Subtracting 55665 from its reverse (56655), we obtain a triangular number (990 = T₄₄).

The spelling of 55665 in words is "fifty-five thousand, six hundred sixty-five".