28126431649 has 2 divisors, whose sum is σ = 28126431650. Its totient is φ = 28126431648.

The previous prime is 28126431647. The next prime is 28126431701. The reversal of 28126431649 is 94613462182.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16707372049 + 11419059600 = 129257^2 + 106860^2 .

It is a cyclic number.

It is not a de Polignac number, because 28126431649 - 2¹ = 28126431647 is a prime.

Together with 28126431647, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 28126431599 and 28126431608.

It is not a weakly prime, because it can be changed into another prime (28126431647) 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 as a sum of consecutive naturals, namely, 14063215824 + 14063215825.

It is an arithmetic number, because the mean of its divisors is an integer number (14063215825).

Almost surely, 2^28126431649 is an apocalyptic number.

It is an amenable number.

28126431649 is a deficient number, since it is larger than the sum of its proper divisors (1).

28126431649 is an equidigital number, since it uses as much as digits as its factorization.

28126431649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 497664, while the sum is 46.

The spelling of 28126431649 in words is "twenty-eight billion, one hundred twenty-six million, four hundred thirty-one thousand, six hundred forty-nine".