28278907729 has 2 divisors, whose sum is σ = 28278907730. Its totient is φ = 28278907728.

The previous prime is 28278907693. The next prime is 28278907747. The reversal of 28278907729 is 92770987282.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16451910225 + 11826997504 = 128265^2 + 108752^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28278907729 is a prime.

It is not a weakly prime, because it can be changed into another prime (28278908729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14139453864 + 14139453865.

It is an arithmetic number, because the mean of its divisors is an integer number (14139453865).

Almost surely, 2^28278907729 is an apocalyptic number.

It is an amenable number.

28278907729 is a deficient number, since it is larger than the sum of its proper divisors (1).

28278907729 is an equidigital number, since it uses as much as digits as its factorization.

28278907729 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14224896, while the sum is 61.

The spelling of 28278907729 in words is "twenty-eight billion, two hundred seventy-eight million, nine hundred seven thousand, seven hundred twenty-nine".