78380009 has 2 divisors, whose sum is σ = 78380010. Its totient is φ = 78380008.

The previous prime is 78379993. The next prime is 78380033. The reversal of 78380009 is 90008387.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 68425984 + 9954025 = 8272^2 + 3155^2 .

It is a cyclic number.

It is not a de Polignac number, because 78380009 - 2⁴ = 78379993 is a prime.

It is a super-2 number, since 2×78380009² = 12286851621680162, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (78380039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39190004 + 39190005.

It is an arithmetic number, because the mean of its divisors is an integer number (39190005).

Almost surely, 2^78380009 is an apocalyptic number.

It is an amenable number.

78380009 is a deficient number, since it is larger than the sum of its proper divisors (1).

78380009 is an equidigital number, since it uses as much as digits as its factorization.

78380009 is an evil number, because the sum of its binary digits is even.

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

The square root of 78380009 is about 8853.2484998446. The cubic root of 78380009 is about 427.9586113790.

The spelling of 78380009 in words is "seventy-eight million, three hundred eighty thousand, nine".