1720688256 has 384 divisors, whose sum is σ = 5965939200. Its totient is φ = 465813504.

The previous prime is 1720688251. The next prime is 1720688261. The reversal of 1720688256 is 6528860271.

It is an interprime number because it is at equal distance from previous prime (1720688251) and next prime (1720688261).

It is a tau number, because it is divible by the number of its divisors (384).

It is not an unprimeable number, because it can be changed into a prime (1720688251) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 21780825 + ... + 21780903.

It is an arithmetic number, because the mean of its divisors is an integer number (15536300).

Almost surely, 2^1720688256 is an apocalyptic number.

1720688256 is a gapful number since it is divisible by the number (16) 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 1720688256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2982969600).

1720688256 is an abundant number, since it is smaller than the sum of its proper divisors (4245250944).

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

1720688256 is a wasteful number, since it uses less digits than its factorization.

1720688256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216 (or 201 counting only the distinct ones).

The product of its (nonzero) digits is 322560, while the sum is 45.

The square root of 1720688256 is about 41481.1795396418. The cubic root of 1720688256 is about 1198.3050738148.

The spelling of 1720688256 in words is "one billion, seven hundred twenty million, six hundred eighty-eight thousand, two hundred fifty-six".