1999243 has 2 divisors, whose sum is σ = 1999244. Its totient is φ = 1999242.

The previous prime is 1999223. The next prime is 1999247. The reversal of 1999243 is 3429991.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1999243 - 2⁵ = 1999211 is a prime.

It is an Ulam number.

1999243 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (1999247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999621 + 999622.

It is an arithmetic number, because the mean of its divisors is an integer number (999622).

2^1999243 is an apocalyptic number.

1999243 is a deficient number, since it is larger than the sum of its proper divisors (1).

1999243 is an equidigital number, since it uses as much as digits as its factorization.

1999243 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17496, while the sum is 37.

The square root of 1999243 is about 1413.9458971262. The cubic root of 1999243 is about 125.9762069796.

The spelling of 1999243 in words is "one million, nine hundred ninety-nine thousand, two hundred forty-three".