255513221 has 2 divisors, whose sum is σ = 255513222. Its totient is φ = 255513220.

The previous prime is 255513217. The next prime is 255513239. The reversal of 255513221 is 122315552.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 142324900 + 113188321 = 11930^2 + 10639^2 .

It is a cyclic number.

It is not a de Polignac number, because 255513221 - 2² = 255513217 is a prime.

It is a super-2 number, since 2×255513221² = 130574012211589682, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (255513241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 127756610 + 127756611.

It is an arithmetic number, because the mean of its divisors is an integer number (127756611).

Almost surely, 2^255513221 is an apocalyptic number.

It is an amenable number.

255513221 is a deficient number, since it is larger than the sum of its proper divisors (1).

255513221 is an equidigital number, since it uses as much as digits as its factorization.

255513221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3000, while the sum is 26.

The square root of 255513221 is about 15984.7809181108. The cubic root of 255513221 is about 634.5577104845.

Adding to 255513221 its reverse (122315552), we get a palindrome (377828773).

The spelling of 255513221 in words is "two hundred fifty-five million, five hundred thirteen thousand, two hundred twenty-one".