78820261252729 has 2 divisors, whose sum is σ = 78820261252730. Its totient is φ = 78820261252728.

The previous prime is 78820261252723. The next prime is 78820261252861. The reversal of 78820261252729 is 92725216202887.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 77386733962729 + 1433527290000 = 8796973^2 + 1197300^2 .

It is an emirp because it is prime and its reverse (92725216202887) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78820261252729 - 2¹⁵ = 78820261219961 is a prime.

It is not a weakly prime, because it can be changed into another prime (78820261252723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39410130626364 + 39410130626365.

It is an arithmetic number, because the mean of its divisors is an integer number (39410130626365).

Almost surely, 2^{78820261252729} is an apocalyptic number.

It is an amenable number.

78820261252729 is a deficient number, since it is larger than the sum of its proper divisors (1).

78820261252729 is an equidigital number, since it uses as much as digits as its factorization.

78820261252729 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27095040, while the sum is 61.

The spelling of 78820261252729 in words is "seventy-eight trillion, eight hundred twenty billion, two hundred sixty-one million, two hundred fifty-two thousand, seven hundred twenty-nine".