999992640 has 112 divisors (see below), whose sum is σ = 3196742400. Its totient is φ = 264837120.

The previous prime is 999992639. The next prime is 999992641. The reversal of 999992640 is 46299999.

999992640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (999992639) and next prime (999992641).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999992641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 139545 + ... + 146535.

Almost surely, 2^999992640 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 999992640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1598371200).

999992640 is an abundant number, since it is smaller than the sum of its proper divisors (2196749760).

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

999992640 is a wasteful number, since it uses less digits than its factorization.

999992640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7160 (or 7150 counting only the distinct ones).

The product of its (nonzero) digits is 2834352, while the sum is 57.

The square root of 999992640 is about 31622.6602296518. The cubic root of 999992640 is about 999.9975466606.

The spelling of 999992640 in words is "nine hundred ninety-nine million, nine hundred ninety-two thousand, six hundred forty".