999997993 has 4 divisors (see below), whose sum is σ = 1000382148. Its totient is φ = 999613840.

The previous prime is 999997967. The next prime is 999998003. The reversal of 999997993 is 399799999.

999997993 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 489825424 + 510172569 = 22132^2 + 22587^2 .

It is a cyclic number.

It is not a de Polignac number, because 999997993 - 2¹³ = 999989801 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (999997793) 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, 188146 + ... + 193387.

It is an arithmetic number, because the mean of its divisors is an integer number (250095537).

Almost surely, 2^999997993 is an apocalyptic number.

It is an amenable number.

999997993 is a deficient number, since it is larger than the sum of its proper divisors (384155).

999997993 is a wasteful number, since it uses less digits than its factorization.

999997993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 384154.

The product of its digits is 100442349, while the sum is 73.

The square root of 999997993 is about 31622.7448682116. The cubic root of 999997993 is about 999.9993309996. Note that the first 3 decimals are identical.

The spelling of 999997993 in words is "nine hundred ninety-nine million, nine hundred ninety-seven thousand, nine hundred ninety-three".