55281 has 4 divisors (see below), whose sum is σ = 73712. Its totient is φ = 36852.

The previous prime is 55259. The next prime is 55291. The reversal of 55281 is 18255.

Added to its reverse (18255) it gives a triangular number (73536 = T₃₈₃).

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 55281 - 2⁵ = 55249 is a prime.

It is a super-2 number, since 2×55281² = 6111977922, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

It is a Curzon number.

55281 is a lucky number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 55281.

It is not an unprimeable number, because it can be changed into a prime (55201) 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 in 3 ways as a sum of consecutive naturals, for example, 9211 + ... + 9216.

It is an arithmetic number, because the mean of its divisors is an integer number (18428).

2⁵⁵²⁸¹ is an apocalyptic number.

It is an amenable number.

55281 is a deficient number, since it is larger than the sum of its proper divisors (18431).

55281 is a wasteful number, since it uses less digits than its factorization.

55281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18430.

The product of its digits is 400, while the sum is 21.

The square root of 55281 is about 235.1191187462. The cubic root of 55281 is about 38.0941800549.

Adding to 55281 its reverse (18255), we get a triangular number (73536 = T₃₈₃).

The spelling of 55281 in words is "fifty-five thousand, two hundred eighty-one".