1997843 has 2 divisors, whose sum is σ = 1997844. Its totient is φ = 1997842.

The previous prime is 1997833. The next prime is 1997851. The reversal of 1997843 is 3487991.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1997843 - 2⁸ = 1997587 is a prime.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1997843.

It is not a weakly prime, because it can be changed into another prime (1997813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 998921 + 998922.

It is an arithmetic number, because the mean of its divisors is an integer number (998922).

2^1997843 is an apocalyptic number.

1997843 is a deficient number, since it is larger than the sum of its proper divisors (1).

1997843 is an equidigital number, since it uses as much as digits as its factorization.

1997843 is an evil number, because the sum of its binary digits is even.

The product of its digits is 54432, while the sum is 41.

The square root of 1997843 is about 1413.4507419787. The cubic root of 1997843 is about 125.9467945347.

The spelling of 1997843 in words is "one million, nine hundred ninety-seven thousand, eight hundred forty-three".