99999998820 has 48 divisors (see below), whose sum is σ = 311111109120. Its totient is φ = 26666666208.

The previous prime is 99999998767. The next prime is 99999998821. The reversal of 99999998820 is 2889999999.

It is a nialpdrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 99999998820.

It is not an unprimeable number, because it can be changed into a prime (99999998821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 92592052 + ... + 92593131.

It is an arithmetic number, because the mean of its divisors is an integer number (6481481440).

Almost surely, 2^99999998820 is an apocalyptic number.

99999998820 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

99999998820 is an abundant number, since it is smaller than the sum of its proper divisors (211111110300).

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

99999998820 is a wasteful number, since it uses less digits than its factorization.

99999998820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 185185201 (or 185185193 counting only the distinct ones).

The product of its (nonzero) digits is 612220032, while the sum is 81.

The spelling of 99999998820 in words is "ninety-nine billion, nine hundred ninety-nine million, nine hundred ninety-eight thousand, eight hundred twenty".