28708405709 has 8 divisors (see below), whose sum is σ = 29556412920. Its totient is φ = 27864193536.

The previous prime is 28708405703. The next prime is 28708405777. The reversal of 28708405709 is 90750480782.

It can be written as a sum of positive squares in 4 ways, for example, as 21960276100 + 6748129609 = 148190^2 + 82147^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28708405709 - 2¹² = 28708401613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28708405703) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 933404 + ... + 963669.

It is an arithmetic number, because the mean of its divisors is an integer number (3694551615).

Almost surely, 2^28708405709 is an apocalyptic number.

It is an amenable number.

28708405709 is a deficient number, since it is larger than the sum of its proper divisors (848007211).

28708405709 is a wasteful number, since it uses less digits than its factorization.

28708405709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1897519.

The product of its (nonzero) digits is 1128960, while the sum is 50.

The spelling of 28708405709 in words is "twenty-eight billion, seven hundred eight million, four hundred five thousand, seven hundred nine".