1990543 has 2 divisors, whose sum is σ = 1990544. Its totient is φ = 1990542.

The previous prime is 1990529. The next prime is 1990553. The reversal of 1990543 is 3450991.

It is a strong prime.

It is an emirp because it is prime and its reverse (3450991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1990543 - 2⁹ = 1990031 is a prime.

It is a super-2 number, since 2×1990543² = 7924522869698, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1990523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 995271 + 995272.

It is an arithmetic number, because the mean of its divisors is an integer number (995272).

2^1990543 is an apocalyptic number.

1990543 is a deficient number, since it is larger than the sum of its proper divisors (1).

1990543 is an equidigital number, since it uses as much as digits as its factorization.

1990543 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4860, while the sum is 31.

The square root of 1990543 is about 1410.8660460866. The cubic root of 1990543 is about 125.7932066061.

The spelling of 1990543 in words is "one million, nine hundred ninety thousand, five hundred forty-three".