78844489 has 2 divisors, whose sum is σ = 78844490. Its totient is φ = 78844488.

The previous prime is 78844429. The next prime is 78844511. The reversal of 78844489 is 98444887.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 57638464 + 21206025 = 7592^2 + 4605^2 .

It is an emirp because it is prime and its reverse (98444887) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78844489 - 2⁷ = 78844361 is a prime.

It is a super-2 number, since 2×78844489² = 12432906891342242, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78844429) 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, 39422244 + 39422245.

It is an arithmetic number, because the mean of its divisors is an integer number (39422245).

Almost surely, 2^78844489 is an apocalyptic number.

It is an amenable number.

78844489 is a deficient number, since it is larger than the sum of its proper divisors (1).

78844489 is an equidigital number, since it uses as much as digits as its factorization.

78844489 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2064384, while the sum is 52.

The square root of 78844489 is about 8879.4419306621. The cubic root of 78844489 is about 428.8023080166.

The spelling of 78844489 in words is "seventy-eight million, eight hundred forty-four thousand, four hundred eighty-nine".