9978722387 has 2 divisors, whose sum is σ = 9978722388. Its totient is φ = 9978722386.

The previous prime is 9978722329. The next prime is 9978722399. The reversal of 9978722387 is 7832278799.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 9978722387 - 2³⁰ = 8904980563 is a prime.

It is not a weakly prime, because it can be changed into another prime (9978724387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4989361193 + 4989361194.

It is an arithmetic number, because the mean of its divisors is an integer number (4989361194).

Almost surely, 2^9978722387 is an apocalyptic number.

9978722387 is a deficient number, since it is larger than the sum of its proper divisors (1).

9978722387 is an equidigital number, since it uses as much as digits as its factorization.

9978722387 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21337344, while the sum is 62.

The square root of 9978722387 is about 99893.5552826107. Note that the first 3 decimals coincide. The cubic root of 9978722387 is about 2152.9055640612.

The spelling of 9978722387 in words is "nine billion, nine hundred seventy-eight million, seven hundred twenty-two thousand, three hundred eighty-seven".