55421 has 4 divisors (see below), whose sum is σ = 55932. Its totient is φ = 54912.

The previous prime is 55411. The next prime is 55439. The reversal of 55421 is 12455.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 19321 + 36100 = 139^2 + 190^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55421 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 55421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55411) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20 + ... + 333.

It is an arithmetic number, because the mean of its divisors is an integer number (13983).

2⁵⁵⁴²¹ is an apocalyptic number.

It is an amenable number.

55421 is a deficient number, since it is larger than the sum of its proper divisors (511).

55421 is a wasteful number, since it uses less digits than its factorization.

55421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 510.

The product of its digits is 200, while the sum is 17.

The square root of 55421 is about 235.4166519174. The cubic root of 55421 is about 38.1263109824.

Adding to 55421 its reverse (12455), we get a palindrome (67876).

It can be divided in two parts, 554 and 21, that added together give a palindrome (575).

The spelling of 55421 in words is "fifty-five thousand, four hundred twenty-one".