78340013 has 4 divisors (see below), whose sum is σ = 79147740. Its totient is φ = 77532288.

The previous prime is 78339997. The next prime is 78340019. The reversal of 78340013 is 31004387.

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

It can be written as a sum of positive squares in 2 ways, for example, as 63075364 + 15264649 = 7942^2 + 3907^2 .

It is a cyclic number.

It is not a de Polignac number, because 78340013 - 2⁴ = 78339997 is a prime.

It is a super-2 number, since 2×78340013² = 12274315273680338, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78340019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 403718 + ... + 403911.

It is an arithmetic number, because the mean of its divisors is an integer number (19786935).

Almost surely, 2^78340013 is an apocalyptic number.

It is an amenable number.

78340013 is a deficient number, since it is larger than the sum of its proper divisors (807727).

78340013 is an equidigital number, since it uses as much as digits as its factorization.

78340013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 807726.

The product of its (nonzero) digits is 2016, while the sum is 26.

The square root of 78340013 is about 8850.9893797247. The cubic root of 78340013 is about 427.8858056338.

The spelling of 78340013 in words is "seventy-eight million, three hundred forty thousand, thirteen".