9999888778 has 8 divisors (see below), whose sum is σ = 16363454400. Its totient is φ = 4545403980.

The previous prime is 9999888751. The next prime is 9999888781. The reversal of 9999888778 is 8778889999.

It is a sphenic number, since it is the product of 3 distinct primes.

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, 227270178 + ... + 227270221.

It is an arithmetic number, because the mean of its divisors is an integer number (2045431800).

Almost surely, 2^9999888778 is an apocalyptic number.

9999888778 is a deficient number, since it is larger than the sum of its proper divisors (6363565622).

9999888778 is a wasteful number, since it uses less digits than its factorization.

9999888778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 454540412.

The product of its digits is 1316818944, while the sum is 82.

The square root of 9999888778 is about 99999.4438884537. The cubic root of 9999888778 is about 2154.4267026511.

The spelling of 9999888778 in words is "nine billion, nine hundred ninety-nine million, eight hundred eighty-eight thousand, seven hundred seventy-eight".