78968391 has 4 divisors (see below), whose sum is σ = 105291192. Its totient is φ = 52645592.

The previous prime is 78968387. The next prime is 78968399. The reversal of 78968391 is 19386987.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 78968391 - 2² = 78968387 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78968399) 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, 13161396 + ... + 13161401.

It is an arithmetic number, because the mean of its divisors is an integer number (26322798).

Almost surely, 2^78968391 is an apocalyptic number.

78968391 is a deficient number, since it is larger than the sum of its proper divisors (26322801).

78968391 is a wasteful number, since it uses less digits than its factorization.

78968391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26322800.

The product of its digits is 653184, while the sum is 51.

The square root of 78968391 is about 8886.4160942418. The cubic root of 78968391 is about 429.0268075684.

The spelling of 78968391 in words is "seventy-eight million, nine hundred sixty-eight thousand, three hundred ninety-one".