681996 has 48 divisors (see below), whose sum is σ = 1903104. Its totient is φ = 185856.

The previous prime is 681983. The next prime is 681997. The reversal of 681996 is 699186.

It is not an unprimeable number, because it can be changed into a prime (681997) by changing a digit.

681996 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1756 + ... + 2108.

It is an arithmetic number, because the mean of its divisors is an integer number (39648).

2⁶⁸¹⁹⁹⁶ 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 681996, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (951552).

681996 is an abundant number, since it is smaller than the sum of its proper divisors (1221108).

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

681996 is a wasteful number, since it uses less digits than its factorization.

681996 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390 (or 388 counting only the distinct ones).

The product of its digits is 23328, while the sum is 39.

The square root of 681996 is about 825.8304910816. The cubic root of 681996 is about 88.0225493178.

The spelling of 681996 in words is "six hundred eighty-one thousand, nine hundred ninety-six".