256661271700 has 36 divisors (see below), whose sum is σ = 556977280860. Its totient is φ = 102660394240.

The previous prime is 256661271673. The next prime is 256661271701. The reversal of 256661271700 is 7172166652.

It can be written as a sum of positive squares in 6 ways, for example, as 16878686724 + 239782584976 = 129918^2 + 489676^2 .

It is a super-2 number, since 2×256661271700² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256661271701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4226754 + ... + 4287046.

It is an arithmetic number, because the mean of its divisors is an integer number (15471591135).

Almost surely, 2^256661271700 is an apocalyptic number.

256661271700 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

256661271700 is an abundant number, since it is smaller than the sum of its proper divisors (300316009160).

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

256661271700 is a wasteful number, since it uses less digits than its factorization.

256661271700 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102876 (or 102869 counting only the distinct ones).

The product of its (nonzero) digits is 211680, while the sum is 43.

The spelling of 256661271700 in words is "two hundred fifty-six billion, six hundred sixty-one million, two hundred seventy-one thousand, seven hundred".