256329991680 has 400 divisors, whose sum is σ = 956042653104. Its totient is φ = 58585497600.

The previous prime is 256329991663. The next prime is 256329991703. The reversal of 256329991680 is 86199923652.

It is a Harshad number since it is a multiple of its sum of digits (60).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 18432730 + ... + 18446630.

Almost surely, 2^256329991680 is an apocalyptic number.

256329991680 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 256329991680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (478021326552).

256329991680 is an abundant number, since it is smaller than the sum of its proper divisors (699712661424).

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

256329991680 is an frugal number, since it uses more digits than its factorization.

256329991680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13955 (or 13918 counting only the distinct ones).

The product of its (nonzero) digits is 12597120, while the sum is 60.

The spelling of 256329991680 in words is "two hundred fifty-six billion, three hundred twenty-nine million, nine hundred ninety-one thousand, six hundred eighty".