9999779944 has 32 divisors (see below), whose sum is σ = 23376110400. Its totient is φ = 3896017920.

The previous prime is 9999779939. The next prime is 9999779953. The reversal of 9999779944 is 4499779999.

It is a zygodrome in base 10.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8116089 + ... + 8117320.

It is an arithmetic number, because the mean of its divisors is an integer number (730503450).

Almost surely, 2^9999779944 is an apocalyptic number.

It is an amenable number.

9999779944 is an abundant number, since it is smaller than the sum of its proper divisors (13376330456).

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

9999779944 is a wasteful number, since it uses less digits than its factorization.

9999779944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16233433 (or 16233429 counting only the distinct ones).

The product of its digits is 416649744, while the sum is 76.

The square root of 9999779944 is about 99998.8997139469. The cubic root of 9999779944 is about 2154.4188867066.

Subtracting from 9999779944 its reverse (4499779999), we obtain a palindrome (5499999945).

The spelling of 9999779944 in words is "nine billion, nine hundred ninety-nine million, seven hundred seventy-nine thousand, nine hundred forty-four".