681611 has 4 divisors (see below), whose sum is σ = 778992. Its totient is φ = 584232.

The previous prime is 681607. The next prime is 681613. The reversal of 681611 is 116186.

It is a happy number.

681611 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.

It is a cyclic number.

It is not a de Polignac number, because 681611 - 2² = 681607 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 681611.

It is not an unprimeable number, because it can be changed into a prime (681613) 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, 48680 + ... + 48693.

It is an arithmetic number, because the mean of its divisors is an integer number (194748).

2⁶⁸¹⁶¹¹ is an apocalyptic number.

681611 is a deficient number, since it is larger than the sum of its proper divisors (97381).

681611 is an equidigital number, since it uses as much as digits as its factorization.

681611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97380.

The product of its digits is 288, while the sum is 23.

The square root of 681611 is about 825.5973594919. The cubic root of 681611 is about 88.0059827200.

Adding to 681611 its reverse (116186), we get a palindrome (797797).

The spelling of 681611 in words is "six hundred eighty-one thousand, six hundred eleven".