999855920 has 40 divisors (see below), whose sum is σ = 2656761504. Its totient is φ = 342807552.

The previous prime is 999855919. The next prime is 999855937. The reversal of 999855920 is 29558999.

999855920 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (56).

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, 892169 + ... + 893288.

Almost surely, 2^999855920 is an apocalyptic number.

It is an amenable number.

999855920 is an abundant number, since it is smaller than the sum of its proper divisors (1656905584).

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

999855920 is a wasteful number, since it uses less digits than its factorization.

999855920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1785477 (or 1785471 counting only the distinct ones).

The product of its (nonzero) digits is 2624400, while the sum is 56.

The square root of 999855920 is about 31620.4984147942. The cubic root of 999855920 is about 999.9519710266.

The spelling of 999855920 in words is "nine hundred ninety-nine million, eight hundred fifty-five thousand, nine hundred twenty".