78891329 has 4 divisors (see below), whose sum is σ = 86063280. Its totient is φ = 71719380.

The previous prime is 78891317. The next prime is 78891331. The reversal of 78891329 is 92319887.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 78891329 - 2¹² = 78887233 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (78891349) 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, 3585959 + ... + 3585980.

It is an arithmetic number, because the mean of its divisors is an integer number (21515820).

Almost surely, 2^78891329 is an apocalyptic number.

It is an amenable number.

78891329 is a deficient number, since it is larger than the sum of its proper divisors (7171951).

78891329 is a wasteful number, since it uses less digits than its factorization.

78891329 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7171950.

The product of its digits is 217728, while the sum is 47.

The square root of 78891329 is about 8882.0790921946. The cubic root of 78891329 is about 428.8872056181.

The spelling of 78891329 in words is "seventy-eight million, eight hundred ninety-one thousand, three hundred twenty-nine".