999988878 has 16 divisors (see below), whose sum is σ = 2285688960. Its totient is φ = 285711096.

The previous prime is 999988877. The next prime is 999988883. The reversal of 999988878 is 878889999.

It is a super-2 number, since 2×999988878² = 1999955512247397768, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999988877) 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, 11904588 + ... + 11904671.

It is an arithmetic number, because the mean of its divisors is an integer number (142855560).

Almost surely, 2^999988878 is an apocalyptic number.

999988878 is an abundant number, since it is smaller than the sum of its proper divisors (1285700082).

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

999988878 is a wasteful number, since it uses less digits than its factorization.

999988878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23809271.

The product of its digits is 188116992, while the sum is 75.

The square root of 999988878 is about 31622.6007469341. The cubic root of 999988878 is about 999.9962926529.

The spelling of 999988878 in words is "nine hundred ninety-nine million, nine hundred eighty-eight thousand, eight hundred seventy-eight".