681978528 has 576 divisors, whose sum is σ = 2694601728. Its totient is φ = 164229120.

The previous prime is 681978509. The next prime is 681978559. The reversal of 681978528 is 825879186.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 10178751 + ... + 10178817.

It is an arithmetic number, because the mean of its divisors is an integer number (4678128).

Almost surely, 2^681978528 is an apocalyptic number.

681978528 is a gapful number since it is divisible by the number (68) 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 681978528, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1347300864).

681978528 is an abundant number, since it is smaller than the sum of its proper divisors (2012623200).

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

681978528 is a wasteful number, since it uses less digits than its factorization.

681978528 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127 (or 107 counting only the distinct ones).

The product of its digits is 1935360, while the sum is 54.

The square root of 681978528 is about 26114.7186084782. The cubic root of 681978528 is about 880.2179763058.

The spelling of 681978528 in words is "six hundred eighty-one million, nine hundred seventy-eight thousand, five hundred twenty-eight".