99991144 has 64 divisors (see below), whose sum is σ = 219283200. Its totient is φ = 42240000.

The previous prime is 99991109. The next prime is 99991207. The reversal of 99991144 is 44119999.

It is a Smith number, since the sum of its digits (46) coincides with the sum of the digits of its prime factors.

It is a zygodrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 99991094 and 99991103.

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 15 ways as a sum of consecutive naturals, for example, 132769 + ... + 133519.

It is an arithmetic number, because the mean of its divisors is an integer number (3426300).

Almost surely, 2^99991144 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 99991144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109641600).

99991144 is an abundant number, since it is smaller than the sum of its proper divisors (119292056).

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

99991144 is a wasteful number, since it uses less digits than its factorization.

99991144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 874 (or 870 counting only the distinct ones).

The product of its digits is 104976, while the sum is 46.

The square root of 99991144 is about 9999.5571901960. The cubic root of 99991144 is about 464.1451809865.

The spelling of 99991144 in words is "ninety-nine million, nine hundred ninety-one thousand, one hundred forty-four".