681528 has 32 divisors (see below), whose sum is σ = 1731600. Its totient is φ = 223488.

The previous prime is 681523. The next prime is 681539. The reversal of 681528 is 825186.

681528 is a nontrivial binomial coefficient, being equal to C(1168, 2).

It is a junction number, because it is equal to n+sod(n) for n = 681495 and 681504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681521) 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, 1558 + ... + 1946.

681528 is a Friedman number, since it can be written as 88^(2+1)+56, using all its digits and the basic arithmetic operations.

2⁶⁸¹⁵²⁸ is an apocalyptic number.

681528 is the 1167-th triangular number and also the 584-th hexagonal number.

It is an amenable number.

681528 is an abundant number, since it is smaller than the sum of its proper divisors (1050072).

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

681528 is a wasteful number, since it uses less digits than its factorization.

681528 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 471 (or 467 counting only the distinct ones).

The product of its digits is 3840, while the sum is 30.

The square root of 681528 is about 825.5470913279. The cubic root of 681528 is about 88.0024104023.

It can be divided in two parts, 68 and 1528, that added together give a triangular number (1596 = T₅₆).

The spelling of 681528 in words is "six hundred eighty-one thousand, five hundred twenty-eight".