681144128 has 56 divisors (see below), whose sum is σ = 1573938432. Its totient is φ = 286401024.

The previous prime is 681144127. The next prime is 681144133. The reversal of 681144128 is 821441186.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (56).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681144127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9401 + ... + 38087.

Almost surely, 2^681144128 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 681144128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (786969216).

681144128 is an abundant number, since it is smaller than the sum of its proper divisors (892794304).

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

681144128 is a wasteful number, since it uses less digits than its factorization.

681144128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28759 (or 28749 counting only the distinct ones).

The product of its digits is 12288, while the sum is 35.

The square root of 681144128 is about 26098.7380537834. The cubic root of 681144128 is about 879.8588478838.

The spelling of 681144128 in words is "six hundred eighty-one million, one hundred forty-four thousand, one hundred twenty-eight".