99128839680 has 480 divisors, whose sum is σ = 372535843680. Its totient is φ = 24215224320.

The previous prime is 99128839651. The next prime is 99128839687. The reversal of 99128839680 is 8693882199.

99128839680 is a `hidden beast` number, since 9 + 91 + 2 + 88 + 396 + 80 = 666.

It is a tau number, because it is divible by the number of its divisors (480).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99128839687) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 41632090 + ... + 41634470.

It is an arithmetic number, because the mean of its divisors is an integer number (776116341).

Almost surely, 2^99128839680 is an apocalyptic number.

99128839680 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 99128839680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (186267921840).

99128839680 is an abundant number, since it is smaller than the sum of its proper divisors (273407004000).

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

99128839680 is a wasteful number, since it uses less digits than its factorization.

99128839680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2562 (or 2543 counting only the distinct ones).

The product of its (nonzero) digits is 13436928, while the sum is 63.

The spelling of 99128839680 in words is "ninety-nine billion, one hundred twenty-eight million, eight hundred thirty-nine thousand, six hundred eighty".