993642891 has 4 divisors (see below), whose sum is σ = 1324857192. Its totient is φ = 662428592.

The previous prime is 993642889. The next prime is 993642893. The reversal of 993642891 is 198246399.

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

It is an interprime number because it is at equal distance from previous prime (993642889) and next prime (993642893).

It is a cyclic number.

It is not a de Polignac number, because 993642891 - 2¹ = 993642889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (993642893) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 165607146 + ... + 165607151.

It is an arithmetic number, because the mean of its divisors is an integer number (331214298).

Almost surely, 2^993642891 is an apocalyptic number.

993642891 is a deficient number, since it is larger than the sum of its proper divisors (331214301).

993642891 is a wasteful number, since it uses less digits than its factorization.

993642891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 331214300.

The product of its digits is 839808, while the sum is 51.

The square root of 993642891 is about 31522.1016272710. The cubic root of 993642891 is about 997.8764574256.

The spelling of 993642891 in words is "nine hundred ninety-three million, six hundred forty-two thousand, eight hundred ninety-one".