256507636 has 48 divisors (see below), whose sum is σ = 562447872. Its totient is φ = 99439200.

The previous prime is 256507631. The next prime is 256507649. The reversal of 256507636 is 636705652.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256507631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 63015 + ... + 66961.

It is an arithmetic number, because the mean of its divisors is an integer number (11717664).

Almost surely, 2^256507636 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256507636, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (281223936).

256507636 is an abundant number, since it is smaller than the sum of its proper divisors (305940236).

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

256507636 is a wasteful number, since it uses less digits than its factorization.

256507636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4180 (or 4178 counting only the distinct ones).

The product of its (nonzero) digits is 226800, while the sum is 40.

The square root of 256507636 is about 16015.8557685813. The cubic root of 256507636 is about 635.3798425949.

The spelling of 256507636 in words is "two hundred fifty-six million, five hundred seven thousand, six hundred thirty-six".