78993689 has 4 divisors (see below), whose sum is σ = 79248000. Its totient is φ = 78739380.

The previous prime is 78993683. The next prime is 78993727. The reversal of 78993689 is 98639987.

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, and also an emirpimes, since its reverse is a distinct semiprime: 98639987 = 131 ⋅752977.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78993689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78993683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 126689 + ... + 127310.

It is an arithmetic number, because the mean of its divisors is an integer number (19812000).

Almost surely, 2^78993689 is an apocalyptic number.

It is an amenable number.

78993689 is a deficient number, since it is larger than the sum of its proper divisors (254311).

78993689 is a wasteful number, since it uses less digits than its factorization.

78993689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 254310.

The product of its digits is 5878656, while the sum is 59.

The square root of 78993689 is about 8887.8393887379. The cubic root of 78993689 is about 429.0726164515.

The spelling of 78993689 in words is "seventy-eight million, nine hundred ninety-three thousand, six hundred eighty-nine".