999824400 has 405 divisors, whose sum is σ = 3808503543.
Its totient is φ = 242841600.
The previous prime is 999824393. The next prime is 999824407. The reversal of 999824400 is 4428999.
Multipling 999824400 by its product of nonzero digits (186624), we get a square (186591228825600 = 136598402).
The square root of 999824400 is 31620.
It is a perfect power (a square), and thus also a powerful number.
It is an interprime number because it is at equal distance from previous prime (999824393) and next prime (999824407).
It can be written as a sum of positive squares in 4 ways, for example, as 23386896 + 976437504 = 4836^2 + 31248^2
It is a Harshad number since it is a multiple of its sum of digits (45).
It is not an unprimeable number, because it can be changed into a prime (999824407) by changing a digit.
It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 32252385 + ... + 32252415.
Almost surely, 2999824400 is an apocalyptic number.
999824400 is a gapful number since it is divisible by the number (90) formed by its first and last digit.
999824400 is the 31620-th square number.
It is an amenable number.
It is a practical number, because each smaller number is the sum of distinct divisors of 999824400
999824400 is an abundant number, since it is smaller than the sum of its proper divisors (2808679143).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
999824400 is a wasteful number, since it uses less digits than its factorization.
999824400 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 120 (or 58 counting only the distinct ones).
The product of its (nonzero) digits is 186624, while the sum is 45.
The cubic root of 999824400 is about 999.9414632402.
The spelling of 999824400 in words is "nine hundred ninety-nine million, eight hundred twenty-four thousand, four hundred".