999156720 has 160 divisors (see below), whose sum is σ = 3242203200. Its totient is φ = 254205952.

The previous prime is 999156713. The next prime is 999156721. The reversal of 999156720 is 27651999.

It is a super-3 number, since 3×999156720³ (a number of 28 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 999156720.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999156721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 618634 + ... + 620246.

It is an arithmetic number, because the mean of its divisors is an integer number (20263770).

Almost surely, 2^999156720 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 999156720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1621101600).

999156720 is an abundant number, since it is smaller than the sum of its proper divisors (2243046480).

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

999156720 is a wasteful number, since it uses less digits than its factorization.

999156720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1747 (or 1741 counting only the distinct ones).

The product of its (nonzero) digits is 306180, while the sum is 48.

The square root of 999156720 is about 31609.4403620184. The cubic root of 999156720 is about 999.7188276162.

The spelling of 999156720 in words is "nine hundred ninety-nine million, one hundred fifty-six thousand, seven hundred twenty".