255421 has 4 divisors (see below), whose sum is σ = 257152. Its totient is φ = 253692.

The previous prime is 255419. The next prime is 255443. The reversal of 255421 is 124552.

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 a cyclic number.

It is not a de Polignac number, because 255421 - 2¹ = 255419 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (255121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 621 + ... + 946.

It is an arithmetic number, because the mean of its divisors is an integer number (64288).

2²⁵⁵⁴²¹ is an apocalyptic number.

It is an amenable number.

255421 is a deficient number, since it is larger than the sum of its proper divisors (1731).

255421 is a wasteful number, since it uses less digits than its factorization.

255421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1730.

The product of its digits is 400, while the sum is 19.

The square root of 255421 is about 505.3919271219. The cubic root of 255421 is about 63.4481358808.

Adding to 255421 its reverse (124552), we get a palindrome (379973).

It can be divided in two parts, 255 and 421, that added together give a palindrome (676).

The spelling of 255421 in words is "two hundred fifty-five thousand, four hundred twenty-one".