78638399 has 8 divisors (see below), whose sum is σ = 89953920. Its totient is φ = 67343256.

The previous prime is 78638387. The next prime is 78638423. The reversal of 78638399 is 99383687.

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

It is a cyclic number.

It is not a de Polignac number, because 78638399 - 2⁸ = 78638143 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 78638399.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78638999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4352 + ... + 13274.

It is an arithmetic number, because the mean of its divisors is an integer number (11244240).

Almost surely, 2^78638399 is an apocalyptic number.

78638399 is a deficient number, since it is larger than the sum of its proper divisors (11315521).

78638399 is a wasteful number, since it uses less digits than its factorization.

78638399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10189.

The product of its digits is 1959552, while the sum is 53.

The square root of 78638399 is about 8867.8294413007. The cubic root of 78638399 is about 428.4283694843.

The spelling of 78638399 in words is "seventy-eight million, six hundred thirty-eight thousand, three hundred ninety-nine".