256640444701720 has 32 divisors (see below), whose sum is σ = 611408118261600. Its totient is φ = 96617579181568.

The previous prime is 256640444701661. The next prime is 256640444701721. The reversal of 256640444701720 is 27107444046652.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256640444701721) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 188706208660 + ... + 188706210019.

It is an arithmetic number, because the mean of its divisors is an integer number (19106503695675).

Almost surely, 2^{256640444701720} is an apocalyptic number.

256640444701720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

256640444701720 is an abundant number, since it is smaller than the sum of its proper divisors (354767673559880).

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

256640444701720 is a wasteful number, since it uses less digits than its factorization.

256640444701720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 377412418707 (or 377412418703 counting only the distinct ones).

The product of its (nonzero) digits is 9031680, while the sum is 52.

The spelling of 256640444701720 in words is "two hundred fifty-six trillion, six hundred forty billion, four hundred forty-four million, seven hundred one thousand, seven hundred twenty".