78809573 has 2 divisors, whose sum is σ = 78809574. Its totient is φ = 78809572.

The previous prime is 78809483. The next prime is 78809581. The reversal of 78809573 is 37590887.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 70845889 + 7963684 = 8417^2 + 2822^2 .

It is a cyclic number.

It is not a de Polignac number, because 78809573 - 2¹² = 78805477 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78809173) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39404786 + 39404787.

It is an arithmetic number, because the mean of its divisors is an integer number (39404787).

Almost surely, 2^78809573 is an apocalyptic number.

It is an amenable number.

78809573 is a deficient number, since it is larger than the sum of its proper divisors (1).

78809573 is an equidigital number, since it uses as much as digits as its factorization.

78809573 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 423360, while the sum is 47.

The square root of 78809573 is about 8877.4755983894. The cubic root of 78809573 is about 428.7390008143.

The spelling of 78809573 in words is "seventy-eight million, eight hundred nine thousand, five hundred seventy-three".