99891985 has 8 divisors (see below), whose sum is σ = 119978496. Its totient is φ = 79841520.

The previous prime is 99891947. The next prime is 99891989. The reversal of 99891985 is 58919899.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 99891985 - 2¹³ = 99883793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99891989) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2481 + ... + 14350.

It is an arithmetic number, because the mean of its divisors is an integer number (14997312).

Almost surely, 2^99891985 is an apocalyptic number.

It is an amenable number.

99891985 is a deficient number, since it is larger than the sum of its proper divisors (20086511).

99891985 is a wasteful number, since it uses less digits than its factorization.

99891985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18023.

The product of its digits is 2099520, while the sum is 58.

The square root of 99891985 is about 9994.5977908068. The cubic root of 99891985 is about 463.9917027475.

The spelling of 99891985 in words is "ninety-nine million, eight hundred ninety-one thousand, nine hundred eighty-five".