9999989977 has 2 divisors, whose sum is σ = 9999989978. Its totient is φ = 9999989976.

The previous prime is 9999989971. The next prime is 9999989983. The reversal of 9999989977 is 7799899999.

9999989977 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is a balanced prime because it is at equal distance from previous prime (9999989971) and next prime (9999989983).

It can be written as a sum of positive squares in only one way, i.e., 9981808281 + 18181696 = 99909^2 + 4264^2 .

It is a cyclic number.

It is not a de Polignac number, because 9999989977 - 2¹⁹ = 9999465689 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 9999989894 and 9999989903.

It is not a weakly prime, because it can be changed into another prime (9999989971) 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 as a sum of consecutive naturals, namely, 4999994988 + 4999994989.

It is an arithmetic number, because the mean of its divisors is an integer number (4999994989).

Almost surely, 2^9999989977 is an apocalyptic number.

It is an amenable number.

9999989977 is a deficient number, since it is larger than the sum of its proper divisors (1).

9999989977 is an equidigital number, since it uses as much as digits as its factorization.

9999989977 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1874923848, while the sum is 85.

The square root of 9999989977 is about 99999.9498849874. The cubic root of 9999989977 is about 2154.4339702350.

The spelling of 9999989977 in words is "nine billion, nine hundred ninety-nine million, nine hundred eighty-nine thousand, nine hundred seventy-seven".