78644359 has 2 divisors, whose sum is σ = 78644360. Its totient is φ = 78644358.

The previous prime is 78644353. The next prime is 78644387. The reversal of 78644359 is 95344687.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 78644359 - 2⁷ = 78644231 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78644353) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39322179 + 39322180.

It is an arithmetic number, because the mean of its divisors is an integer number (39322180).

Almost surely, 2^78644359 is an apocalyptic number.

78644359 is a deficient number, since it is larger than the sum of its proper divisors (1).

78644359 is an equidigital number, since it uses as much as digits as its factorization.

78644359 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 725760, while the sum is 46.

The square root of 78644359 is about 8868.1654810902. The cubic root of 78644359 is about 428.4391927319.

It can be divided in two parts, 78644 and 359, that added together give a triangular number (79003 = T₃₉₇).

The spelling of 78644359 in words is "seventy-eight million, six hundred forty-four thousand, three hundred fifty-nine".