1999993 has 2 divisors, whose sum is σ = 1999994.
Its totient is φ = 1999992.
The previous prime is 1999979. The next prime is 2000003. The reversal of 1999993 is 3999991.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 1272384 + 727609 = 1128^2 + 853^2
It is a cyclic number.
It is a de Polignac number, because none of the positive numbers 2k-1999993 is a prime.
It is not a weakly prime, because it can be changed into another prime (1991993) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (11) of ones.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999996 + 999997.
It is an arithmetic number, because the mean of its divisors is an integer number (999997).
21999993 is an apocalyptic number.
It is an amenable number.
1999993 is a deficient number, since it is larger than the sum of its proper divisors (1).
1999993 is an equidigital number, since it uses as much as digits as its factorization.
1999993 is an odious number, because the sum of its binary digits is odd.
The product of its digits is 177147, while the sum is 49.
The square root of 1999993 is about 1414.2110874972.
The cubic root of 1999993 is about 125.9919579985.
It can be divided in two parts, 199999 and 3, that added together give a palindrome (200002).
The spelling of 1999993 in words is "one million, nine hundred ninety-nine thousand, nine hundred ninety-three".