78472117 has 4 divisors (see below), whose sum is σ = 78815020. Its totient is φ = 78129216.

The previous prime is 78472087. The next prime is 78472151. The reversal of 78472117 is 71127487.

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 62583921 + 15888196 = 7911^2 + 3986^2 .

It is a cyclic number.

It is not a de Polignac number, because 78472117 - 2¹⁹ = 77947829 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 (78472217) 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, 171108 + ... + 171565.

It is an arithmetic number, because the mean of its divisors is an integer number (19703755).

Almost surely, 2^78472117 is an apocalyptic number.

It is an amenable number.

78472117 is a deficient number, since it is larger than the sum of its proper divisors (342903).

78472117 is a wasteful number, since it uses less digits than its factorization.

78472117 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 342902.

The product of its digits is 21952, while the sum is 37.

The square root of 78472117 is about 8858.4489048591. The cubic root of 78472117 is about 428.1261837892.

The spelling of 78472117 in words is "seventy-eight million, four hundred seventy-two thousand, one hundred seventeen".