255221220 has 48 divisors (see below), whose sum is σ = 715393728. Its totient is φ = 67985280.

The previous prime is 255221209. The next prime is 255221231. The reversal of 255221220 is 22122552.

It is an interprime number because it is at equal distance from previous prime (255221209) and next prime (255221231).

It is a super-2 number, since 2×255221220² = 130275742276576800, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 74955 + ... + 78285.

It is an arithmetic number, because the mean of its divisors is an integer number (14904036).

Almost surely, 2^255221220 is an apocalyptic number.

255221220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

255221220 is an abundant number, since it is smaller than the sum of its proper divisors (460172508).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

255221220 is a wasteful number, since it uses less digits than its factorization.

255221220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4620 (or 4618 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 21.

The square root of 255221220 is about 15975.6445879345. The cubic root of 255221220 is about 634.3158937546.

Adding to 255221220 its reverse (22122552), we get a palindrome (277343772).

The spelling of 255221220 in words is "two hundred fifty-five million, two hundred twenty-one thousand, two hundred twenty".