256875635240 has 128 divisors (see below), whose sum is σ = 690145781760. Its totient is φ = 84133741824.

The previous prime is 256875635227. The next prime is 256875635249. The reversal of 256875635240 is 42536578652.

It is a happy number.

It is a Cunningham number, because it is equal to 506829²-1.

It is not an unprimeable number, because it can be changed into a prime (256875635249) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5042939 + ... + 5093621.

It is an arithmetic number, because the mean of its divisors is an integer number (5391763920).

Almost surely, 2^256875635240 is an apocalyptic number.

256875635240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256875635240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (345072890880).

256875635240 is an abundant number, since it is smaller than the sum of its proper divisors (433270146520).

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

256875635240 is a wasteful number, since it uses less digits than its factorization.

256875635240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51511 (or 51507 counting only the distinct ones).

The product of its (nonzero) digits is 12096000, while the sum is 53.

The spelling of 256875635240 in words is "two hundred fifty-six billion, eight hundred seventy-five million, six hundred thirty-five thousand, two hundred forty".