78439853 has 4 divisors (see below), whose sum is σ = 83053980. Its totient is φ = 73825728.

The previous prime is 78439813. The next prime is 78439859. The reversal of 78439853 is 35893487.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 35893487 = 7 ⋅5127641.

It can be written as a sum of positive squares in 2 ways, for example, as 54213769 + 24226084 = 7363^2 + 4922^2 .

It is a cyclic number.

It is not a de Polignac number, because 78439853 - 2⁸ = 78439597 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 78439798 and 78439807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78439859) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2307038 + ... + 2307071.

It is an arithmetic number, because the mean of its divisors is an integer number (20763495).

Almost surely, 2^78439853 is an apocalyptic number.

It is an amenable number.

78439853 is a deficient number, since it is larger than the sum of its proper divisors (4614127).

78439853 is a wasteful number, since it uses less digits than its factorization.

78439853 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4614126.

The product of its digits is 725760, while the sum is 47.

The square root of 78439853 is about 8856.6276313279. The cubic root of 78439853 is about 428.0675007085.

The spelling of 78439853 in words is "seventy-eight million, four hundred thirty-nine thousand, eight hundred fifty-three".