9999888780 has 48 divisors (see below), whose sum is σ = 31999645440. Its totient is φ = 2285688768.

The previous prime is 9999888751. The next prime is 9999888781. The reversal of 9999888780 is 878889999.

It is a super-2 number, since 2×9999888780² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (9999888781) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11904210 + ... + 11905049.

It is an arithmetic number, because the mean of its divisors is an integer number (666659280).

Almost surely, 2^9999888780 is an apocalyptic number.

It is an amenable number.

9999888780 is an abundant number, since it is smaller than the sum of its proper divisors (21999756660).

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

9999888780 is a wasteful number, since it uses less digits than its factorization.

9999888780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23809278 (or 23809276 counting only the distinct ones).

The product of its (nonzero) digits is 188116992, while the sum is 75.

The square root of 9999888780 is about 99999.4438984538. The cubic root of 9999888780 is about 2154.4267027947.

The spelling of 9999888780 in words is "nine billion, nine hundred ninety-nine million, eight hundred eighty-eight thousand, seven hundred eighty".