78144569 has 2 divisors, whose sum is σ = 78144570. Its totient is φ = 78144568.

The previous prime is 78144559. The next prime is 78144601. The reversal of 78144569 is 96544187.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 69222400 + 8922169 = 8320^2 + 2987^2 .

It is a cyclic number.

It is not a de Polignac number, because 78144569 - 2⁴ = 78144553 is a prime.

It is a super-2 number, since 2×78144569² = 12213147328391522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (78144559) 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, 39072284 + 39072285.

It is an arithmetic number, because the mean of its divisors is an integer number (39072285).

Almost surely, 2^78144569 is an apocalyptic number.

It is an amenable number.

78144569 is a deficient number, since it is larger than the sum of its proper divisors (1).

78144569 is an equidigital number, since it uses as much as digits as its factorization.

78144569 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 241920, while the sum is 44.

The square root of 78144569 is about 8839.9416853280. The cubic root of 78144569 is about 427.5296770433.

The spelling of 78144569 in words is "seventy-eight million, one hundred forty-four thousand, five hundred sixty-nine".