78889399 has 4 divisors (see below), whose sum is σ = 78999840. Its totient is φ = 78778960.

The previous prime is 78889381. The next prime is 78889411. The reversal of 78889399 is 99398887.

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 78889399 - 2⁷ = 78889271 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78889319) 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, 54142 + ... + 55579.

It is an arithmetic number, because the mean of its divisors is an integer number (19749960).

Almost surely, 2^78889399 is an apocalyptic number.

78889399 is a deficient number, since it is larger than the sum of its proper divisors (110441).

78889399 is a wasteful number, since it uses less digits than its factorization.

78889399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110440.

The product of its digits is 7838208, while the sum is 61.

The square root of 78889399 is about 8881.9704457964. The cubic root of 78889399 is about 428.8837081528.

The spelling of 78889399 in words is "seventy-eight million, eight hundred eighty-nine thousand, three hundred ninety-nine".