78338391 has 8 divisors (see below), whose sum is σ = 108992640. Its totient is φ = 49954872.

The previous prime is 78338383. The next prime is 78338419. The reversal of 78338391 is 19383387.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 78338391 - 2³ = 78338383 is a prime.

It is a super-2 number, since 2×78338391² = 12273807008937762, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78338321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 567601 + ... + 567738.

It is an arithmetic number, because the mean of its divisors is an integer number (13624080).

Almost surely, 2^78338391 is an apocalyptic number.

78338391 is a deficient number, since it is larger than the sum of its proper divisors (30654249).

78338391 is a wasteful number, since it uses less digits than its factorization.

78338391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1135365.

The product of its digits is 108864, while the sum is 42.

The square root of 78338391 is about 8850.8977510759. The cubic root of 78338391 is about 427.8828525428.

The spelling of 78338391 in words is "seventy-eight million, three hundred thirty-eight thousand, three hundred ninety-one".