99878 has 4 divisors (see below), whose sum is σ = 149820. Its totient is φ = 49938.

The previous prime is 99877. The next prime is 99881. The reversal of 99878 is 87899.

99878 is nontrivially palindromic in base 14.

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

It is a super-3 number, since 3×99878³ = 2989033390152456, which contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 24968 + ... + 24971.

It is an arithmetic number, because the mean of its divisors is an integer number (37455).

2⁹⁹⁸⁷⁸ is an apocalyptic number.

99878 is a deficient number, since it is larger than the sum of its proper divisors (49942).

99878 is a wasteful number, since it uses less digits than its factorization.

99878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49941.

The product of its digits is 36288, while the sum is 41.

The square root of 99878 is about 316.0348082095. The cubic root of 99878 is about 46.3970048602.

The spelling of 99878 in words is "ninety-nine thousand, eight hundred seventy-eight".