683991 has 48 divisors (see below), whose sum is σ = 1313280. Its totient is φ = 347760.

The previous prime is 683983. The next prime is 684007. The reversal of 683991 is 199386.

It is not a de Polignac number, because 683991 - 2³ = 683983 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

Its product of digits (11664) is a multiple of the sum of its prime factors (81).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (683911) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 14530 + ... + 14576.

It is an arithmetic number, because the mean of its divisors is an integer number (27360).

2⁶⁸³⁹⁹¹ is an apocalyptic number.

683991 is a deficient number, since it is larger than the sum of its proper divisors (629289).

683991 is a wasteful number, since it uses less digits than its factorization.

683991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81 (or 68 counting only the distinct ones).

The product of its digits is 11664, while the sum is 36.

The square root of 683991 is about 827.0374840356. The cubic root of 683991 is about 88.1082947058.

The spelling of 683991 in words is "six hundred eighty-three thousand, nine hundred ninety-one".