78044389 has 2 divisors, whose sum is σ = 78044390. Its totient is φ = 78044388.

The previous prime is 78044387. The next prime is 78044401. The reversal of 78044389 is 98344087.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 78021889 + 22500 = 8833^2 + 150^2 .

It is an emirp because it is prime and its reverse (98344087) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78044389 - 2¹ = 78044387 is a prime.

Together with 78044387, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78044387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39022194 + 39022195.

It is an arithmetic number, because the mean of its divisors is an integer number (39022195).

Almost surely, 2^78044389 is an apocalyptic number.

It is an amenable number.

78044389 is a deficient number, since it is larger than the sum of its proper divisors (1).

78044389 is an equidigital number, since it uses as much as digits as its factorization.

78044389 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 193536, while the sum is 43.

The square root of 78044389 is about 8834.2735411578. The cubic root of 78044389 is about 427.3469036740.

The spelling of 78044389 in words is "seventy-eight million, forty-four thousand, three hundred eighty-nine".