999696640 has 72 divisors (see below), whose sum is σ = 2401229880. Its totient is φ = 398770176.

The previous prime is 999696631. The next prime is 999696641. The reversal of 999696640 is 46696999.

It can be written as a sum of positive squares in 4 ways, for example, as 122589184 + 877107456 = 11072^2 + 29616^2 .

It is not an unprimeable number, because it can be changed into a prime (999696641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 584106 + ... + 585814.

It is an arithmetic number, because the mean of its divisors is an integer number (33350415).

Almost surely, 2^999696640 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 999696640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1200614940).

999696640 is an abundant number, since it is smaller than the sum of its proper divisors (1401533240).

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

999696640 is a wasteful number, since it uses less digits than its factorization.

999696640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2187 (or 2173 counting only the distinct ones).

The product of its (nonzero) digits is 5668704, while the sum is 58.

The square root of 999696640 is about 31617.9796951039. The cubic root of 999696640 is about 999.8988697730.

The spelling of 999696640 in words is "nine hundred ninety-nine million, six hundred ninety-six thousand, six hundred forty".