681617 has 4 divisors (see below), whose sum is σ = 683520. Its totient is φ = 679716.

The previous prime is 681613. The next prime is 681623. The reversal of 681617 is 716186.

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 not a de Polignac number, because 681617 - 2² = 681613 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 681617.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 681617.

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, 233 + ... + 1190.

It is an arithmetic number, because the mean of its divisors is an integer number (170880).

2⁶⁸¹⁶¹⁷ is an apocalyptic number.

It is an amenable number.

681617 is a deficient number, since it is larger than the sum of its proper divisors (1903).

681617 is a wasteful number, since it uses less digits than its factorization.

681617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1902.

The product of its digits is 2016, while the sum is 29.

The square root of 681617 is about 825.6009932165. The cubic root of 681617 is about 88.0062409486.

The spelling of 681617 in words is "six hundred eighty-one thousand, six hundred seventeen".