999161856 has 324 divisors, whose sum is σ = 3625961976. Its totient is φ = 259522560.

The previous prime is 999161843. The next prime is 999161857. The reversal of 999161856 is 658161999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999161857) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 90832891 + ... + 90832901.

Almost surely, 2^999161856 is an apocalyptic number.

999161856 is a gapful number since it is divisible by the number (96) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 999161856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1812980988).

999161856 is an abundant number, since it is smaller than the sum of its proper divisors (2626800120).

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

999161856 is an equidigital number, since it uses as much as digits as its factorization.

999161856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69 (or 23 counting only the distinct ones).

The product of its digits is 1049760, while the sum is 54.

The square root of 999161856 is about 31609.5216034663. The cubic root of 999161856 is about 999.7205405764.

The spelling of 999161856 in words is "nine hundred ninety-nine million, one hundred sixty-one thousand, eight hundred fifty-six".