681641 has 4 divisors (see below), whose sum is σ = 696192. Its totient is φ = 667092.

The previous prime is 681631. The next prime is 681647. The reversal of 681641 is 146186.

681641 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-681641 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 681641.

It is not an unprimeable number, because it can be changed into a prime (681647) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7205 + ... + 7298.

It is an arithmetic number, because the mean of its divisors is an integer number (174048).

2⁶⁸¹⁶⁴¹ is an apocalyptic number.

It is an amenable number.

681641 is a deficient number, since it is larger than the sum of its proper divisors (14551).

681641 is a wasteful number, since it uses less digits than its factorization.

681641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14550.

The product of its digits is 1152, while the sum is 26.

The square root of 681641 is about 825.6155279547. The cubic root of 681641 is about 88.0072738478.

The spelling of 681641 in words is "six hundred eighty-one thousand, six hundred forty-one".