78478685 has 4 divisors (see below), whose sum is σ = 94174428. Its totient is φ = 62782944.

The previous prime is 78478657. The next prime is 78478703. The reversal of 78478685 is 58687487.

It is a happy number.

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 14830201 + 63648484 = 3851^2 + 7978^2 .

It is a cyclic number.

It is not a de Polignac number, because 78478685 - 2¹⁶ = 78413149 is a prime.

It is a Duffinian number.

It is a plaindrome in base 13.

It is a congruent number.

It is an unprimeable number.

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, 7847864 + ... + 7847873.

It is an arithmetic number, because the mean of its divisors is an integer number (23543607).

Almost surely, 2^78478685 is an apocalyptic number.

It is an amenable number.

78478685 is a deficient number, since it is larger than the sum of its proper divisors (15695743).

78478685 is a wasteful number, since it uses less digits than its factorization.

78478685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15695742.

The product of its digits is 3010560, while the sum is 53.

The square root of 78478685 is about 8858.8196166306. The cubic root of 78478685 is about 428.1381279651.

The spelling of 78478685 in words is "seventy-eight million, four hundred seventy-eight thousand, six hundred eighty-five".