1990843 has 4 divisors (see below), whose sum is σ = 1993680. Its totient is φ = 1988008.

The previous prime is 1990831. The next prime is 1990867. The reversal of 1990843 is 3480991.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1990843 - 2¹⁷ = 1859771 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1990799 and 1990808.

It is not an unprimeable number, because it can be changed into a prime (1990823) 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, 498 + ... + 2056.

It is an arithmetic number, because the mean of its divisors is an integer number (498420).

2^1990843 is an apocalyptic number.

1990843 is a deficient number, since it is larger than the sum of its proper divisors (2837).

1990843 is a wasteful number, since it uses less digits than its factorization.

1990843 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2836.

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 1990843 is about 1410.9723597576. The cubic root of 1990843 is about 125.7995258310.

The spelling of 1990843 in words is "one million, nine hundred ninety thousand, eight hundred forty-three".