28209811968 has 240 divisors, whose sum is σ = 92839042296. Its totient is φ = 8169062400.

The previous prime is 28209811963. The next prime is 28209811979. The reversal of 28209811968 is 86911890282.

It can be written as a sum of positive squares in 4 ways, for example, as 22155727104 + 6054084864 = 148848^2 + 77808^2 .

It is not an unprimeable number, because it can be changed into a prime (28209811963) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1004518 + ... + 1032218.

Almost surely, 2^28209811968 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 28209811968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46419521148).

28209811968 is an abundant number, since it is smaller than the sum of its proper divisors (64629230328).

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

28209811968 is a wasteful number, since it uses less digits than its factorization.

28209811968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27755 (or 27736 counting only the distinct ones).

The product of its (nonzero) digits is 995328, while the sum is 54.

The spelling of 28209811968 in words is "twenty-eight billion, two hundred nine million, eight hundred eleven thousand, nine hundred sixty-eight".