99859987 has 4 divisors (see below), whose sum is σ = 99884520. Its totient is φ = 99835456.

The previous prime is 99859979. The next prime is 99859999. The reversal of 99859987 is 78995899.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78995899 = 947 ⋅83417.

It is a cyclic number.

It is not a de Polignac number, because 99859987 - 2³ = 99859979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99859927) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 4537 + ... + 14842.

It is an arithmetic number, because the mean of its divisors is an integer number (24971130).

Almost surely, 2^99859987 is an apocalyptic number.

99859987 is a deficient number, since it is larger than the sum of its proper divisors (24533).

99859987 is a wasteful number, since it uses less digits than its factorization.

99859987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24532.

The product of its digits is 14696640, while the sum is 64.

The square root of 99859987 is about 9992.9968978280. The cubic root of 99859987 is about 463.9421545878.

The spelling of 99859987 in words is "ninety-nine million, eight hundred fifty-nine thousand, nine hundred eighty-seven".