78317939 has 4 divisors (see below), whose sum is σ = 89506224. Its totient is φ = 67129656.

The previous prime is 78317881. The next prime is 78317959. The reversal of 78317939 is 93971387.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78317939 is a prime.

It is a super-2 number, since 2×78317939² = 12267399138415442, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 78317893 and 78317902.

It is not an unprimeable number, because it can be changed into a prime (78317959) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5594132 + ... + 5594145.

It is an arithmetic number, because the mean of its divisors is an integer number (22376556).

Almost surely, 2^78317939 is an apocalyptic number.

78317939 is a deficient number, since it is larger than the sum of its proper divisors (11188285).

78317939 is a wasteful number, since it uses less digits than its factorization.

78317939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11188284.

The product of its digits is 285768, while the sum is 47.

The square root of 78317939 is about 8849.7423126326. The cubic root of 78317939 is about 427.8456131525.

The spelling of 78317939 in words is "seventy-eight million, three hundred seventeen thousand, nine hundred thirty-nine".