255821240 has 16 divisors (see below), whose sum is σ = 575597880. Its totient is φ = 102328480.

The previous prime is 255821231. The next prime is 255821243. The reversal of 255821240 is 42128552.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (255821243) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 3197726 + ... + 3197805.

Almost surely, 2^255821240 is an apocalyptic number.

255821240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

255821240 is an abundant number, since it is smaller than the sum of its proper divisors (319776640).

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

255821240 is a wasteful number, since it uses less digits than its factorization.

255821240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6395542 (or 6395538 counting only the distinct ones).

The product of its (nonzero) digits is 6400, while the sum is 29.

The square root of 255821240 is about 15994.4127744660. The cubic root of 255821240 is about 634.8125927213.

Adding to 255821240 its reverse (42128552), we get a palindrome (297949792).

The spelling of 255821240 in words is "two hundred fifty-five million, eight hundred twenty-one thousand, two hundred forty".