78423173 has 2 divisors, whose sum is σ = 78423174. Its totient is φ = 78423172.

The previous prime is 78423161. The next prime is 78423179. The reversal of 78423173 is 37132487.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 48469444 + 29953729 = 6962^2 + 5473^2 .

It is a cyclic number.

It is not a de Polignac number, because 78423173 - 2⁸ = 78422917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78423179) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39211586 + 39211587.

It is an arithmetic number, because the mean of its divisors is an integer number (39211587).

Almost surely, 2^78423173 is an apocalyptic number.

It is an amenable number.

78423173 is a deficient number, since it is larger than the sum of its proper divisors (1).

78423173 is an equidigital number, since it uses as much as digits as its factorization.

78423173 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 28224, while the sum is 35.

The square root of 78423173 is about 8855.6859135812. The cubic root of 78423173 is about 428.0371561332.

The spelling of 78423173 in words is "seventy-eight million, four hundred twenty-three thousand, one hundred seventy-three".