78409171 has 4 divisors (see below), whose sum is σ = 79738200. Its totient is φ = 77080144.

The previous prime is 78409157. The next prime is 78409189. The reversal of 78409171 is 17190487.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17190487 = 523 ⋅32869.

It is a cyclic number.

It is not a de Polignac number, because 78409171 - 2¹¹ = 78407123 is a prime.

It is a super-2 number, since 2×78409171² = 12295996193814482, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 78409171.

It is not an unprimeable number, because it can be changed into a prime (78409871) 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, 664426 + ... + 664543.

It is an arithmetic number, because the mean of its divisors is an integer number (19934550).

Almost surely, 2^78409171 is an apocalyptic number.

78409171 is a deficient number, since it is larger than the sum of its proper divisors (1329029).

78409171 is a wasteful number, since it uses less digits than its factorization.

78409171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1329028.

The product of its (nonzero) digits is 14112, while the sum is 37.

The square root of 78409171 is about 8854.8953127634. The cubic root of 78409171 is about 428.0116801046.

The spelling of 78409171 in words is "seventy-eight million, four hundred nine thousand, one hundred seventy-one".