78406841 has 4 divisors (see below), whose sum is σ = 78447732. Its totient is φ = 78365952.

The previous prime is 78406819. The next prime is 78406871. The reversal of 78406841 is 14860487.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 14860487 = 3191 ⋅4657.

It can be written as a sum of positive squares in 2 ways, for example, as 73891216 + 4515625 = 8596^2 + 2125^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78406841 is a prime.

It is a super-2 number, since 2×78406841² = 12295265431198562, 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 = 78406795 and 78406804.

It is not an unprimeable number, because it can be changed into a prime (78406871) 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, 17420 + ... + 21453.

It is an arithmetic number, because the mean of its divisors is an integer number (19611933).

Almost surely, 2^78406841 is an apocalyptic number.

It is an amenable number.

78406841 is a deficient number, since it is larger than the sum of its proper divisors (40891).

78406841 is a wasteful number, since it uses less digits than its factorization.

78406841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40890.

The product of its (nonzero) digits is 43008, while the sum is 38.

The square root of 78406841 is about 8854.7637461425. The cubic root of 78406841 is about 428.0074404768.

The spelling of 78406841 in words is "seventy-eight million, four hundred six thousand, eight hundred forty-one".