78432917 has 4 divisors (see below), whose sum is σ = 83046636. Its totient is φ = 73819200.

The previous prime is 78432899. The next prime is 78432923. The reversal of 78432917 is 71923487.

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 62504836 + 15928081 = 7906^2 + 3991^2 .

It is a cyclic number.

It is not a de Polignac number, because 78432917 - 2¹⁸ = 78170773 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78432997) 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, 2306834 + ... + 2306867.

It is an arithmetic number, because the mean of its divisors is an integer number (20761659).

Almost surely, 2^78432917 is an apocalyptic number.

It is an amenable number.

78432917 is a deficient number, since it is larger than the sum of its proper divisors (4613719).

78432917 is a wasteful number, since it uses less digits than its factorization.

78432917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4613718.

The product of its digits is 84672, while the sum is 41.

The square root of 78432917 is about 8856.2360515063. The cubic root of 78432917 is about 428.0548831270.

The spelling of 78432917 in words is "seventy-eight million, four hundred thirty-two thousand, nine hundred seventeen".