999997992 has 48 divisors (see below), whose sum is σ = 3095233440. Its totient is φ = 285713568.

The previous prime is 999997967. The next prime is 999998003. The reversal of 999997992 is 299799999.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 999997992.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 991558 + ... + 992565.

It is an arithmetic number, because the mean of its divisors is an integer number (64484030).

Almost surely, 2^999997992 is an apocalyptic number.

It is an amenable number.

999997992 is an abundant number, since it is smaller than the sum of its proper divisors (2095235448).

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

999997992 is a wasteful number, since it uses less digits than its factorization.

999997992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1984142 (or 1984135 counting only the distinct ones).

The product of its digits is 66961566, while the sum is 72.

The square root of 999997992 is about 31622.7448524001. The cubic root of 999997992 is about 999.9993306662. Note that the first 3 decimals are identical.

It can be divided in two parts, 999 and 997992, that added together give a triangular number (998991 = T₁₄₁₃).

The spelling of 999997992 in words is "nine hundred ninety-nine million, nine hundred ninety-seven thousand, nine hundred ninety-two".