309991020768 has 288 divisors, whose sum is σ = 1036435956192. Its totient is φ = 86645145600.

The previous prime is 309991020767. The next prime is 309991020817. The reversal of 309991020768 is 867020199903.

It is a tau number, because it is divible by the number of its divisors (288).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (309991020767) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 85702096 + ... + 85705712.

It is an arithmetic number, because the mean of its divisors is an integer number (3598735959).

Almost surely, 2^309991020768 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 309991020768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (518217978096).

309991020768 is an abundant number, since it is smaller than the sum of its proper divisors (726444935424).

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

309991020768 is a wasteful number, since it uses less digits than its factorization.

309991020768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5738 (or 5727 counting only the distinct ones).

The product of its (nonzero) digits is 1469664, while the sum is 54.

The spelling of 309991020768 in words is "three hundred nine billion, nine hundred ninety-one million, twenty thousand, seven hundred sixty-eight".