309221916872 has 108 divisors (see below), whose sum is σ = 650128543155. Its totient is φ = 137779382400.

The previous prime is 309221916859. The next prime is 309221916881. The reversal of 309221916872 is 278619122903.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in 5 ways, for example, as 138284321956 + 170937594916 = 371866^2 + 413446^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=393206.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 309221916872.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 1055364758 + ... + 1055365050.

Almost surely, 2^309221916872 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 309221916872

309221916872 is an abundant number, since it is smaller than the sum of its proper divisors (340906626283).

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

309221916872 is an equidigital number, since it uses as much as digits as its factorization.

309221916872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 736 (or 367 counting only the distinct ones).

The product of its (nonzero) digits is 653184, while the sum is 50.

Multiplying 309221916872 by its sum of digits (50), we get a square (15461095843600 = 3932060²).

The spelling of 309221916872 in words is "three hundred nine billion, two hundred twenty-one million, nine hundred sixteen thousand, eight hundred seventy-two".