9978722345 has 4 divisors (see below), whose sum is σ = 11974466820. Its totient is φ = 7982977872.

The previous prime is 9978722329. The next prime is 9978722387. The reversal of 9978722345 is 5432278799.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5432278799 = 71 ⋅76510969.

It can be written as a sum of positive squares in 2 ways, for example, as 2550351001 + 7428371344 = 50501^2 + 86188^2 .

It is a cyclic number.

It is not a de Polignac number, because 9978722345 - 2⁴ = 9978722329 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 997872230 + ... + 997872239.

It is an arithmetic number, because the mean of its divisors is an integer number (2993616705).

Almost surely, 2^9978722345 is an apocalyptic number.

It is an amenable number.

9978722345 is a deficient number, since it is larger than the sum of its proper divisors (1995744475).

9978722345 is a wasteful number, since it uses less digits than its factorization.

9978722345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1995744474.

The product of its digits is 7620480, while the sum is 56.

The square root of 9978722345 is about 99893.5550723869. Note that the first 3 decimals coincide. The cubic root of 9978722345 is about 2152.9055610407.

The spelling of 9978722345 in words is "nine billion, nine hundred seventy-eight million, seven hundred twenty-two thousand, three hundred forty-five".