28705090709 has 2 divisors, whose sum is σ = 28705090710. Its totient is φ = 28705090708.

The previous prime is 28705090649. The next prime is 28705090727. The reversal of 28705090709 is 90709050782.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28151806225 + 553284484 = 167785^2 + 23522^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28705090709 is a prime.

It is a super-2 number, since 2×28705090709² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28705090759) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14352545354 + 14352545355.

It is an arithmetic number, because the mean of its divisors is an integer number (14352545355).

Almost surely, 2^28705090709 is an apocalyptic number.

It is an amenable number.

28705090709 is a deficient number, since it is larger than the sum of its proper divisors (1).

28705090709 is an equidigital number, since it uses as much as digits as its factorization.

28705090709 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 317520, while the sum is 47.

The spelling of 28705090709 in words is "twenty-eight billion, seven hundred five million, ninety thousand, seven hundred nine".