99939840 has 480 divisors, whose sum is σ = 431329536. Its totient is φ = 19169280.

The previous prime is 99939797. The next prime is 99939841. The reversal of 99939840 is 4893999.

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 (99939841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7687674 + ... + 7687686.

Almost surely, 2^99939840 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 99939840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (215664768).

99939840 is an abundant number, since it is smaller than the sum of its proper divisors (331389696).

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

99939840 is a wasteful number, since it uses less digits than its factorization.

99939840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70 (or 41 counting only the distinct ones).

The product of its (nonzero) digits is 629856, while the sum is 51.

The square root of 99939840 is about 9996.9915474607. The cubic root of 99939840 is about 464.0657853615.

It can be divided in two parts, 99 and 939840, that added together give a palindrome (939939).

The spelling of 99939840 in words is "ninety-nine million, nine hundred thirty-nine thousand, eight hundred forty".