999856020 has 192 divisors, whose sum is σ = 3099672576. Its totient is φ = 239708160.

The previous prime is 999855991. The next prime is 999856021. The reversal of 999856020 is 20658999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999856021) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3256707 + ... + 3257013.

It is an arithmetic number, because the mean of its divisors is an integer number (16144128).

Almost surely, 2^999856020 is an apocalyptic number.

It is a pronic number, being equal to 31620×31621.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 999856020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1549836288).

999856020 is an abundant number, since it is smaller than the sum of its proper divisors (2099816556).

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

999856020 is a wasteful number, since it uses less digits than its factorization.

999856020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 470 (or 468 counting only the distinct ones).

The product of its (nonzero) digits is 349920, while the sum is 48.

The square root of 999856020 is about 31620.4999960469. The cubic root of 999856020 is about 999.9520043631.

The spelling of 999856020 in words is "nine hundred ninety-nine million, eight hundred fifty-six thousand, twenty".