1997543 has 2 divisors, whose sum is σ = 1997544. Its totient is φ = 1997542.

The previous prime is 1997539. The next prime is 1997557. The reversal of 1997543 is 3457991.

It is a happy number.

It is a weak prime.

It is an emirp because it is prime and its reverse (3457991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1997543 - 2² = 1997539 is a prime.

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 1997497 and 1997506.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1997503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 998771 + 998772.

It is an arithmetic number, because the mean of its divisors is an integer number (998772).

2^1997543 is an apocalyptic number.

1997543 is a deficient number, since it is larger than the sum of its proper divisors (1).

1997543 is an equidigital number, since it uses as much as digits as its factorization.

1997543 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34020, while the sum is 38.

The square root of 1997543 is about 1413.3446147348. The cubic root of 1997543 is about 125.9404900804.

The spelling of 1997543 in words is "one million, nine hundred ninety-seven thousand, five hundred forty-three".