9977997798 has 20 divisors (see below), whose sum is σ = 22358106540. Its totient is φ = 3325999212.

The previous prime is 9977997791. The next prime is 9977997853. The reversal of 9977997798 is 8977997799.

It is a happy number.

9977997798 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (81).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9977997791) 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 in 9 ways as a sum of consecutive naturals, for example, 30796128 + ... + 30796451.

It is an arithmetic number, because the mean of its divisors is an integer number (1117905327).

Almost surely, 2^9977997798 is an apocalyptic number.

9977997798 is an abundant number, since it is smaller than the sum of its proper divisors (12380108742).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

9977997798 is a wasteful number, since it uses less digits than its factorization.

9977997798 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61592593 (or 61592584 counting only the distinct ones).

The product of its digits is 1134213192, while the sum is 81.

The square root of 9977997798 is about 99889.9284112267. The cubic root of 9977997798 is about 2152.8534528661.

Subtracting from 9977997798 its reverse (8977997799), we obtain a palindrome (999999999).

The spelling of 9977997798 in words is "nine billion, nine hundred seventy-seven million, nine hundred ninety-seven thousand, seven hundred ninety-eight".