681912 has 128 divisors (see below), whose sum is σ = 2419200. Its totient is φ = 172800.

The previous prime is 681899. The next prime is 681913. The reversal of 681912 is 219186.

It is a Harshad number since it is a multiple of its sum of digits (27).

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

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681913) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 16612 + ... + 16652.

It is an arithmetic number, because the mean of its divisors is an integer number (18900).

2⁶⁸¹⁹¹² 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 681912, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1209600).

681912 is an abundant number, since it is smaller than the sum of its proper divisors (1737288).

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

681912 is a wasteful number, since it uses less digits than its factorization.

681912 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74 (or 64 counting only the distinct ones).

The product of its digits is 864, while the sum is 27.

The square root of 681912 is about 825.7796316209. The cubic root of 681912 is about 88.0189353193.

It can be divided in two parts, 6 and 81912, that added together give a palindrome (81918).

The spelling of 681912 in words is "six hundred eighty-one thousand, nine hundred twelve".