255021221 has 16 divisors (see below), whose sum is σ = 324000768. Its totient is φ = 195264000.

The previous prime is 255021167. The next prime is 255021227. The reversal of 255021221 is 122120552.

It is a happy number.

255021221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 255021221 - 2¹⁰ = 255020197 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 255021193 and 255021202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (255021227) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42380 + ... + 48021.

It is an arithmetic number, because the mean of its divisors is an integer number (20250048).

Almost surely, 2^255021221 is an apocalyptic number.

It is an amenable number.

255021221 is a deficient number, since it is larger than the sum of its proper divisors (68979547).

255021221 is a wasteful number, since it uses less digits than its factorization.

255021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90452.

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

The square root of 255021221 is about 15969.3838641320. The cubic root of 255021221 is about 634.1501608052.

Adding to 255021221 its reverse (122120552), we get a palindrome (377141773).

The spelling of 255021221 in words is "two hundred fifty-five million, twenty-one thousand, two hundred twenty-one".