256219840 has 28 divisors (see below), whose sum is σ = 610124256. Its totient is φ = 102487808.

The previous prime is 256219837. The next prime is 256219841. The reversal of 256219840 is 48912652.

It is a self number, because there is not a number n which added to its sum of digits gives 256219840.

It is not an unprimeable number, because it can be changed into a prime (256219841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 400024 + ... + 400663.

It is an arithmetic number, because the mean of its divisors is an integer number (21790152).

Almost surely, 2^256219840 is an apocalyptic number.

256219840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

256219840 is an abundant number, since it is smaller than the sum of its proper divisors (353904416).

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

256219840 is an equidigital number, since it uses as much as digits as its factorization.

256219840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 800704 (or 800694 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 37.

The square root of 256219840 is about 16006.8685257298. The cubic root of 256219840 is about 635.1421262045.

The spelling of 256219840 in words is "two hundred fifty-six million, two hundred nineteen thousand, eight hundred forty".