999540864 has 256 divisors, whose sum is σ = 3420672000. Its totient is φ = 281428992.

The previous prime is 999540851. The next prime is 999540881. The reversal of 999540864 is 468045999.

999540864 is a `hidden beast` number, since 9 + 99 + 540 + 8 + 6 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 999540864.

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 31 ways as a sum of consecutive naturals, for example, 1910907 + ... + 1911429.

It is an arithmetic number, because the mean of its divisors is an integer number (13362000).

Almost surely, 2^999540864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 999540864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1710336000).

999540864 is an abundant number, since it is smaller than the sum of its proper divisors (2421131136).

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

999540864 is a wasteful number, since it uses less digits than its factorization.

999540864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 632 (or 614 counting only the distinct ones).

The product of its (nonzero) digits is 2799360, while the sum is 54.

The square root of 999540864 is about 31615.5161906302. The cubic root of 999540864 is about 999.8469312378.

The spelling of 999540864 in words is "nine hundred ninety-nine million, five hundred forty thousand, eight hundred sixty-four".