78239417 has 2 divisors, whose sum is σ = 78239418. Its totient is φ = 78239416.

The previous prime is 78239407. The next prime is 78239449. The reversal of 78239417 is 71493287.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 69572281 + 8667136 = 8341^2 + 2944^2 .

It is a cyclic number.

It is not a de Polignac number, because 78239417 - 2⁴ = 78239401 is a prime.

It is a super-2 number, since 2×78239417² = 12242812744999778, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (78239407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39119708 + 39119709.

It is an arithmetic number, because the mean of its divisors is an integer number (39119709).

Almost surely, 2^78239417 is an apocalyptic number.

It is an amenable number.

78239417 is a deficient number, since it is larger than the sum of its proper divisors (1).

78239417 is an equidigital number, since it uses as much as digits as its factorization.

78239417 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 84672, while the sum is 41.

The square root of 78239417 is about 8845.3047997228. The cubic root of 78239417 is about 427.7025785445.

The spelling of 78239417 in words is "seventy-eight million, two hundred thirty-nine thousand, four hundred seventeen".