78745729 has 2 divisors, whose sum is σ = 78745730. Its totient is φ = 78745728.

The previous prime is 78745691. The next prime is 78745739. The reversal of 78745729 is 92754787.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 56655729 + 22090000 = 7527^2 + 4700^2 .

It is a cyclic number.

It is not a de Polignac number, because 78745729 - 2⁹ = 78745217 is a prime.

It is not a weakly prime, because it can be changed into another prime (78745739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39372864 + 39372865.

It is an arithmetic number, because the mean of its divisors is an integer number (39372865).

Almost surely, 2^78745729 is an apocalyptic number.

It is an amenable number.

78745729 is a deficient number, since it is larger than the sum of its proper divisors (1).

78745729 is an equidigital number, since it uses as much as digits as its factorization.

78745729 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 987840, while the sum is 49.

The square root of 78745729 is about 8873.8790277984. The cubic root of 78745729 is about 428.6231950538.

The spelling of 78745729 in words is "seventy-eight million, seven hundred forty-five thousand, seven hundred twenty-nine".