99985791 has 4 divisors (see below), whose sum is σ = 133314392. Its totient is φ = 66657192.

The previous prime is 99985777. The next prime is 99985799. The reversal of 99985791 is 19758999.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 99985791 - 2⁶ = 99985727 is a prime.

It is a Duffinian number.

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99985799) 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 3 ways as a sum of consecutive naturals, for example, 16664296 + ... + 16664301.

It is an arithmetic number, because the mean of its divisors is an integer number (33328598).

Almost surely, 2^99985791 is an apocalyptic number.

99985791 is a deficient number, since it is larger than the sum of its proper divisors (33328601).

99985791 is a wasteful number, since it uses less digits than its factorization.

99985791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33328600.

The product of its digits is 1837080, while the sum is 57.

The square root of 99985791 is about 9999.2895247612. The cubic root of 99985791 is about 464.1368982080.

The spelling of 99985791 in words is "ninety-nine million, nine hundred eighty-five thousand, seven hundred ninety-one".