683981 has 4 divisors (see below), whose sum is σ = 720000. Its totient is φ = 647964.

The previous prime is 683957. The next prime is 683983. The reversal of 683981 is 189386.

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, and also an emirpimes, since its reverse is a distinct semiprime: 189386 = 2 ⋅94693.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-683981 is a prime.

It is a super-2 number, since 2×683981² = 935660016722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 683981.

It is not an unprimeable number, because it can be changed into a prime (683983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17981 + ... + 18018.

It is an arithmetic number, because the mean of its divisors is an integer number (180000).

2⁶⁸³⁹⁸¹ is an apocalyptic number.

It is an amenable number.

683981 is a deficient number, since it is larger than the sum of its proper divisors (36019).

683981 is a wasteful number, since it uses less digits than its factorization.

683981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36018.

The product of its digits is 10368, while the sum is 35.

The square root of 683981 is about 827.0314383383. The cubic root of 683981 is about 88.1078653204.

The spelling of 683981 in words is "six hundred eighty-three thousand, nine hundred eighty-one".