992981993 has 4 divisors (see below), whose sum is σ = 1017201108. Its totient is φ = 968762880.

The previous prime is 992981947. The next prime is 992981999. The reversal of 992981993 is 399189299.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 399189299 = 157 ⋅2542607.

It can be written as a sum of positive squares in 2 ways, for example, as 418325209 + 574656784 = 20453^2 + 23972^2 .

It is a cyclic number.

It is not a de Polignac number, because 992981993 - 2¹⁰ = 992980969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (992981999) 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, 12109496 + ... + 12109577.

It is an arithmetic number, because the mean of its divisors is an integer number (254300277).

Almost surely, 2^992981993 is an apocalyptic number.

It is an amenable number.

992981993 is a deficient number, since it is larger than the sum of its proper divisors (24219115).

992981993 is a wasteful number, since it uses less digits than its factorization.

992981993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24219114.

The product of its digits is 2834352, while the sum is 59.

The square root of 992981993 is about 31511.6167944458. The cubic root of 992981993 is about 997.6551704050.

The spelling of 992981993 in words is "nine hundred ninety-two million, nine hundred eighty-one thousand, nine hundred ninety-three".