78106409 has 2 divisors, whose sum is σ = 78106410. Its totient is φ = 78106408.

The previous prime is 78106393. The next prime is 78106417. The reversal of 78106409 is 90460187.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 43626025 + 34480384 = 6605^2 + 5872^2 .

It is an emirp because it is prime and its reverse (90460187) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78106409 - 2⁴ = 78106393 is a prime.

It is a super-2 number, since 2×78106409² = 12201222253750562, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (78106499) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39053204 + 39053205.

It is an arithmetic number, because the mean of its divisors is an integer number (39053205).

Almost surely, 2^78106409 is an apocalyptic number.

It is an amenable number.

78106409 is a deficient number, since it is larger than the sum of its proper divisors (1).

78106409 is an equidigital number, since it uses as much as digits as its factorization.

78106409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 78106409 is about 8837.7830364860. The cubic root of 78106409 is about 427.4600744720.

The spelling of 78106409 in words is "seventy-eight million, one hundred six thousand, four hundred nine".