999966240 has 432 divisors, whose sum is σ = 4230128448. Its totient is φ = 210622464.

The previous prime is 999966221. The next prime is 999966251. The reversal of 999966240 is 42669999.

999966240 is a `hidden beast` number, since 9 + 9 + 9 + 9 + 6 + 624 + 0 = 666.

It is a super-2 number, since 2×999966240² = 1999864962279475200, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1703227 + ... + 1703813.

It is an arithmetic number, because the mean of its divisors is an integer number (9791964).

Almost surely, 2^999966240 is an apocalyptic number.

999966240 is a gapful number since it is divisible by the number (90) 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 999966240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2115064224).

999966240 is an abundant number, since it is smaller than the sum of its proper divisors (3230162208).

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

999966240 is a wasteful number, since it uses less digits than its factorization.

999966240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 641 (or 617 counting only the distinct ones).

The product of its (nonzero) digits is 1889568, while the sum is 54.

The square root of 999966240 is about 31622.2428047095. The cubic root of 999966240 is about 999.9887465400.

The spelling of 999966240 in words is "nine hundred ninety-nine million, nine hundred sixty-six thousand, two hundred forty".