99998640 has 120 divisors (see below), whose sum is σ = 383823648. Its totient is φ = 22855680.

The previous prime is 99998611. The next prime is 99998663. The reversal of 99998640 is 4689999.

It is a happy number.

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

It is a nialpdrome in base 10.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4881 + ... + 14960.

Almost surely, 2^99998640 is an apocalyptic number.

99998640 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

99998640 is an abundant number, since it is smaller than the sum of its proper divisors (283825008).

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

99998640 is a wasteful number, since it uses less digits than its factorization.

99998640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19867 (or 19858 counting only the distinct ones).

The product of its (nonzero) digits is 1259712, while the sum is 54.

The square root of 99998640 is about 9999.9319997688. The cubic root of 99998640 is about 464.1567791648.

The spelling of 99998640 in words is "ninety-nine million, nine hundred ninety-eight thousand, six hundred forty".