1993813 has 4 divisors (see below), whose sum is σ = 2005920.
Its totient is φ = 1981708.
The previous prime is 1993763. The next prime is 1993829. The reversal of 1993813 is 3183991.
It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.
It is a cyclic number.
It is a de Polignac number, because none of the positive numbers 2k-1993813 is a prime.
It is a Duffinian number.
1993813 is a lucky number.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (1993513) 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, 5803 + ... + 6136.
It is an arithmetic number, because the mean of its divisors is an integer number (501480).
21993813 is an apocalyptic number.
It is an amenable number.
1993813 is a deficient number, since it is larger than the sum of its proper divisors (12107).
1993813 is a wasteful number, since it uses less digits than its factorization.
1993813 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 12106.
The product of its digits is 5832, while the sum is 34.
The square root of 1993813 is about 1412.0244332164.
The cubic root of 1993813 is about 125.8620519318.
The spelling of 1993813 in words is "one million, nine hundred ninety-three thousand, eight hundred thirteen".