19994543 has 4 divisors (see below), whose sum is σ = 20684040. Its totient is φ = 19305048.

The previous prime is 19994539. The next prime is 19994549. The reversal of 19994543 is 34549991.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 19994543 - 2² = 19994539 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 19994494 and 19994503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19994549) 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, 344705 + ... + 344762.

It is an arithmetic number, because the mean of its divisors is an integer number (5171010).

Almost surely, 2^19994543 is an apocalyptic number.

19994543 is a deficient number, since it is larger than the sum of its proper divisors (689497).

19994543 is an equidigital number, since it uses as much as digits as its factorization.

19994543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 689496.

The product of its digits is 174960, while the sum is 44.

The square root of 19994543 is about 4471.5258022290. The cubic root of 19994543 is about 271.4170717856.

The spelling of 19994543 in words is "nineteen million, nine hundred ninety-four thousand, five hundred forty-three".