78432169817 has 2 divisors, whose sum is σ = 78432169818. Its totient is φ = 78432169816.

The previous prime is 78432169813. The next prime is 78432169861. The reversal of 78432169817 is 71896123487.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 42797679376 + 35634490441 = 206876^2 + 188771^2 .

It is a cyclic number.

It is not a de Polignac number, because 78432169817 - 2² = 78432169813 is a prime.

It is not a weakly prime, because it can be changed into another prime (78432169811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39216084908 + 39216084909.

It is an arithmetic number, because the mean of its divisors is an integer number (39216084909).

Almost surely, 2^78432169817 is an apocalyptic number.

It is an amenable number.

78432169817 is a deficient number, since it is larger than the sum of its proper divisors (1).

78432169817 is an equidigital number, since it uses as much as digits as its factorization.

78432169817 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4064256, while the sum is 56.

The spelling of 78432169817 in words is "seventy-eight billion, four hundred thirty-two million, one hundred sixty-nine thousand, eight hundred seventeen".