7989840745 has 4 divisors (see below), whose sum is σ = 9587808900. Its totient is φ = 6391872592.

The previous prime is 7989840743. The next prime is 7989840751. The reversal of 7989840745 is 5470489897.

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 1836379609 + 6153461136 = 42853^2 + 78444^2 .

It is a cyclic number.

It is not a de Polignac number, because 7989840745 - 2¹ = 7989840743 is a prime.

It is not an unprimeable number, because it can be changed into a prime (7989840743) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 798984070 + ... + 798984079.

It is an arithmetic number, because the mean of its divisors is an integer number (2396952225).

Almost surely, 2^7989840745 is an apocalyptic number.

It is an amenable number.

7989840745 is a deficient number, since it is larger than the sum of its proper divisors (1597968155).

7989840745 is a wasteful number, since it uses less digits than its factorization.

7989840745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1597968154.

The product of its (nonzero) digits is 20321280, while the sum is 61.

The square root of 7989840745 is about 89385.9090964566. The cubic root of 7989840745 is about 1999.1530367940.

The spelling of 7989840745 in words is "seven billion, nine hundred eighty-nine million, eight hundred forty thousand, seven hundred forty-five".