255501221 has 4 divisors (see below), whose sum is σ = 257451744. Its totient is φ = 253550700.

The previous prime is 255501209. The next prime is 255501251. The reversal of 255501221 is 122105552.

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 255501221 - 2¹⁴ = 255484837 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 (255501251) 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, 975065 + ... + 975326.

It is an arithmetic number, because the mean of its divisors is an integer number (64362936).

Almost surely, 2^255501221 is an apocalyptic number.

It is an amenable number.

255501221 is a deficient number, since it is larger than the sum of its proper divisors (1950523).

255501221 is a wasteful number, since it uses less digits than its factorization.

255501221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1950522.

The product of its (nonzero) digits is 1000, while the sum is 23.

The square root of 255501221 is about 15984.4055566668. The cubic root of 255501221 is about 634.5477764758.

Adding to 255501221 its reverse (122105552), we get a palindrome (377606773).

The spelling of 255501221 in words is "two hundred fifty-five million, five hundred one thousand, two hundred twenty-one".