99640128 has 224 divisors, whose sum is σ = 329184000. Its totient is φ = 26492928.

The previous prime is 99640067. The next prime is 99640129. The reversal of 99640128 is 82104699.

It is a tau number, because it is divible by the number of its divisors (224).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99640129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1119508 + ... + 1119596.

Almost surely, 2^99640128 is an apocalyptic number.

99640128 is a gapful number since it is divisible by the number (98) 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 99640128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (164592000).

99640128 is an abundant number, since it is smaller than the sum of its proper divisors (229543872).

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

99640128 is a wasteful number, since it uses less digits than its factorization.

99640128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142 (or 118 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 39.

The square root of 99640128 is about 9981.9901823234. The cubic root of 99640128 is about 463.6014214902.

The spelling of 99640128 in words is "ninety-nine million, six hundred forty thousand, one hundred twenty-eight".