999984078 has 24 divisors (see below), whose sum is σ = 2168185968. Its totient is φ = 333088992.

The previous prime is 999984077. The next prime is 999984091. The reversal of 999984078 is 870489999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999984077) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6850 + ... + 45242.

It is an arithmetic number, because the mean of its divisors is an integer number (90341082).

Almost surely, 2^999984078 is an apocalyptic number.

999984078 is an abundant number, since it is smaller than the sum of its proper divisors (1168201890).

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

999984078 is a wasteful number, since it uses less digits than its factorization.

999984078 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39848 (or 39845 counting only the distinct ones).

The product of its (nonzero) digits is 11757312, while the sum is 63.

The square root of 999984078 is about 31622.5248517572. The cubic root of 999984078 is about 999.9946926385.

The spelling of 999984078 in words is "nine hundred ninety-nine million, nine hundred eighty-four thousand, seventy-eight".