99991500 has 192 divisors, whose sum is σ = 339655680. Its totient is φ = 22387200.

The previous prime is 99991499. The next prime is 99991517. The reversal of 99991500 is 519999.

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

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 63 ways as a sum of consecutive naturals, for example, 934447 + ... + 934553.

It is an arithmetic number, because the mean of its divisors is an integer number (1769040).

Almost surely, 2^99991500 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 99991500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (169827840).

99991500 is an abundant number, since it is smaller than the sum of its proper divisors (239664180).

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

99991500 is a wasteful number, since it uses less digits than its factorization.

99991500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 225 (or 213 counting only the distinct ones).

The product of its (nonzero) digits is 32805, while the sum is 42.

The square root of 99991500 is about 9999.5749909684. The cubic root of 99991500 is about 464.1457318203.

The spelling of 99991500 in words is "ninety-nine million, nine hundred ninety-one thousand, five hundred".