55280 has 20 divisors (see below), whose sum is σ = 128712. Its totient is φ = 22080.

The previous prime is 55259. The next prime is 55291. The reversal of 55280 is 8255.

55280 = T₇₅ + T₇₆ + ... + T₉₀.

It is a tau number, because it is divible by the number of its divisors (20).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 266 + ... + 425.

2⁵⁵²⁸⁰ is an apocalyptic number.

It is an amenable number.

55280 is an abundant number, since it is smaller than the sum of its proper divisors (73432).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (64356).

55280 is a wasteful number, since it uses less digits than its factorization.

55280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 704 (or 698 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 20.

The square root of 55280 is about 235.1169921550. The cubic root of 55280 is about 38.0939503533.

It can be divided in two parts, 55 and 280, that multiplied together give a triangular number (15400 = T₁₇₅).

The spelling of 55280 in words is "fifty-five thousand, two hundred eighty".