28388252808361 has 4 divisors (see below), whose sum is σ = 28777132983892. Its totient is φ = 27999372632832.

The previous prime is 28388252808353. The next prime is 28388252808379. The reversal of 28388252808361 is 16380825288382.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 21245830862400 + 7142421945961 = 4609320^2 + 2672531^2 .

It is a cyclic number.

It is not a de Polignac number, because 28388252808361 - 2³ = 28388252808353 is a prime.

It is a super-2 number, since 2×28388252808361² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28388252808293 and 28388252808302.

It is not an unprimeable number, because it can be changed into a prime (28388252808761) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 194440087656 + ... + 194440087801.

It is an arithmetic number, because the mean of its divisors is an integer number (7194283245973).

Almost surely, 2^{28388252808361} is an apocalyptic number.

It is an amenable number.

28388252808361 is a deficient number, since it is larger than the sum of its proper divisors (388880175531).

28388252808361 is an equidigital number, since it uses as much as digits as its factorization.

28388252808361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 388880175530.

The product of its (nonzero) digits is 70778880, while the sum is 64.

The spelling of 28388252808361 in words is "twenty-eight trillion, three hundred eighty-eight billion, two hundred fifty-two million, eight hundred eight thousand, three hundred sixty-one".