999990816 has 48 divisors (see below), whose sum is σ = 2863613088. Its totient is φ = 303027200.

The previous prime is 999990809. The next prime is 999990833. The reversal of 999990816 is 618099999.

It is a tau number, because it is divible by the number of its divisors (48).

It is a self number, because there is not a number n which added to its sum of digits gives 999990816.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 472425 + ... + 474536.

It is an arithmetic number, because the mean of its divisors is an integer number (59658606).

Almost surely, 2^999990816 is an apocalyptic number.

999990816 is a gapful number since it is divisible by the number (96) formed by its first and last digit.

It is an amenable number.

999990816 is an abundant number, since it is smaller than the sum of its proper divisors (1863622272).

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

999990816 is a wasteful number, since it uses less digits than its factorization.

999990816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 946985 (or 946977 counting only the distinct ones).

The product of its (nonzero) digits is 2834352, while the sum is 60.

The square root of 999990816 is about 31622.6313895602. The cubic root of 999990816 is about 999.9969386573.

The spelling of 999990816 in words is "nine hundred ninety-nine million, nine hundred ninety thousand, eight hundred sixteen".