681129792 has 126 divisors (see below), whose sum is σ = 2271178338. Its totient is φ = 194600448.

The previous prime is 681129763. The next prime is 681129811. The reversal of 681129792 is 297921186.

It can be written as a sum of positive squares in only one way, i.e., 569108736 + 112021056 = 23856^2 + 10584^2 .

It is a tau number, because it is divible by the number of its divisors (126).

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a nude number because it is divisible by every one of its digits.

It is a nialpdrome in base 14.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 16158 + ... + 40290.

Almost surely, 2^681129792 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 681129792, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1135589169).

681129792 is an abundant number, since it is smaller than the sum of its proper divisors (1590048546).

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

681129792 is a wasteful number, since it uses less digits than its factorization.

681129792 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24165 (or 24145 counting only the distinct ones).

The product of its digits is 108864, while the sum is 45.

The square root of 681129792 is about 26098.4634030435. The cubic root of 681129792 is about 879.8526750615.

The spelling of 681129792 in words is "six hundred eighty-one million, one hundred twenty-nine thousand, seven hundred ninety-two".