256209521418 has 16 divisors (see below), whose sum is σ = 569354492160. Its totient is φ = 85403173788.

The previous prime is 256209521377. The next prime is 256209521443. The reversal of 256209521418 is 814125902652.

256209521418 is a `hidden beast` number, since 2 + 5 + 6 + 209 + 5 + 21 + 418 = 666.

256209521418 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 2372310330 + ... + 2372310437.

It is an arithmetic number, because the mean of its divisors is an integer number (35584655760).

Almost surely, 2^256209521418 is an apocalyptic number.

256209521418 is an abundant number, since it is smaller than the sum of its proper divisors (313144970742).

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

256209521418 is a wasteful number, since it uses less digits than its factorization.

256209521418 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4744620778 (or 4744620772 counting only the distinct ones).

The product of its (nonzero) digits is 345600, while the sum is 45.

The spelling of 256209521418 in words is "two hundred fifty-six billion, two hundred nine million, five hundred twenty-one thousand, four hundred eighteen".