99643512780 has 288 divisors, whose sum is σ = 361393643520. Its totient is φ = 21746856960.

The previous prime is 99643512767. The next prime is 99643512797. The reversal of 99643512780 is 8721534699.

99643512780 is a `hidden beast` number, since 9 + 9 + 6 + 43 + 512 + 7 + 80 = 666.

99643512780 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2407501 + ... + 2448539.

It is an arithmetic number, because the mean of its divisors is an integer number (1254839040).

It is a 1-persistent number, because it is pandigital, but 2⋅99643512780 = 199287025560 is not.

Almost surely, 2^99643512780 is an apocalyptic number.

99643512780 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 99643512780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (180696821760).

99643512780 is an abundant number, since it is smaller than the sum of its proper divisors (261750130740).

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

99643512780 is a wasteful number, since it uses less digits than its factorization.

99643512780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41149 (or 41144 counting only the distinct ones).

The product of its (nonzero) digits is 3265920, while the sum is 54.

The spelling of 99643512780 in words is "ninety-nine billion, six hundred forty-three million, five hundred twelve thousand, seven hundred eighty".