78505543 has 2 divisors, whose sum is σ = 78505544. Its totient is φ = 78505542.

The previous prime is 78505519. The next prime is 78505591. The reversal of 78505543 is 34550587.

It is a weak prime.

It is an emirp because it is prime and its reverse (34550587) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78505543 - 2¹³ = 78497351 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78505513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39252771 + 39252772.

It is an arithmetic number, because the mean of its divisors is an integer number (39252772).

Almost surely, 2^78505543 is an apocalyptic number.

78505543 is a deficient number, since it is larger than the sum of its proper divisors (1).

78505543 is an equidigital number, since it uses as much as digits as its factorization.

78505543 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 84000, while the sum is 37.

The square root of 78505543 is about 8860.3353773997. The cubic root of 78505543 is about 428.1869634008.

The spelling of 78505543 in words is "seventy-eight million, five hundred five thousand, five hundred forty-three".