99840240 has 120 divisors (see below), whose sum is σ = 349932960. Its totient is φ = 25462272.

The previous prime is 99840229. The next prime is 99840259. The reversal of 99840240 is 4204899.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 99840195 and 99840204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13546 + ... + 19574.

It is an arithmetic number, because the mean of its divisors is an integer number (2916108).

Almost surely, 2^99840240 is an apocalyptic number.

99840240 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 99840240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (174966480).

99840240 is an abundant number, since it is smaller than the sum of its proper divisors (250092720).

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

99840240 is a wasteful number, since it uses less digits than its factorization.

99840240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6071 (or 6062 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 99840240 is about 9992.0088070418. The cubic root of 99840240 is about 463.9115715353.

The spelling of 99840240 in words is "ninety-nine million, eight hundred forty thousand, two hundred forty".