256725360726640 has 80 divisors (see below), whose sum is σ = 642912052557600. Its totient is φ = 94774497555456.

The previous prime is 256725360726613. The next prime is 256725360726649. The reversal of 256725360726640 is 46627063527652.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256725360726649) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15347455 + ... + 27367774.

It is an arithmetic number, because the mean of its divisors is an integer number (8036400656970).

Almost surely, 2^{256725360726640} is an apocalyptic number.

256725360726640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

256725360726640 is an abundant number, since it is smaller than the sum of its proper divisors (386186691830960).

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

256725360726640 is a wasteful number, since it uses less digits than its factorization.

256725360726640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42721034 (or 42721028 counting only the distinct ones).

The product of its (nonzero) digits is 152409600, while the sum is 61.

The spelling of 256725360726640 in words is "two hundred fifty-six trillion, seven hundred twenty-five billion, three hundred sixty million, seven hundred twenty-six thousand, six hundred forty".