256820531700 has 144 divisors (see below), whose sum is σ = 788113307520. Its totient is φ = 64347463680.

The previous prime is 256820531647. The next prime is 256820531731. The reversal of 256820531700 is 7135028652.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2981841 + ... + 3066759.

It is an arithmetic number, because the mean of its divisors is an integer number (5473009080).

Almost surely, 2^256820531700 is an apocalyptic number.

256820531700 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 256820531700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (394056653760).

256820531700 is an abundant number, since it is smaller than the sum of its proper divisors (531292775820).

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

256820531700 is a wasteful number, since it uses less digits than its factorization.

256820531700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85546 (or 85539 counting only the distinct ones).

The product of its (nonzero) digits is 100800, while the sum is 39.

The spelling of 256820531700 in words is "two hundred fifty-six billion, eight hundred twenty million, five hundred thirty-one thousand, seven hundred".