9991993 has 4 divisors (see below), whose sum is σ = 10900368. Its totient is φ = 9083620.

The previous prime is 9991973. The next prime is 9991997. The reversal of 9991993 is 3991999.

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 not a de Polignac number, because 9991993 - 2²¹ = 7894841 is a prime.

It is a super-2 number, since 2×9991993² = 199679848224098, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9991997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 454171 + ... + 454192.

It is an arithmetic number, because the mean of its divisors is an integer number (2725092).

Almost surely, 2^9991993 is an apocalyptic number.

It is an amenable number.

9991993 is a deficient number, since it is larger than the sum of its proper divisors (908375).

9991993 is a wasteful number, since it uses less digits than its factorization.

9991993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 908374.

The product of its digits is 177147, while the sum is 49.

The square root of 9991993 is about 3161.0113887805. The cubic root of 9991993 is about 215.3859517872.

It can be divided in two parts, 999 and 1993, that added together give a palindrome (2992).

The spelling of 9991993 in words is "nine million, nine hundred ninety-one thousand, nine hundred ninety-three".