78677939 has 4 divisors (see below), whose sum is σ = 78763560. Its totient is φ = 78592320.

The previous prime is 78677933. The next prime is 78677959. The reversal of 78677939 is 93977687.

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 78677939 - 2⁴ = 78677923 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78677933) 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, 41417 + ... + 43274.

It is an arithmetic number, because the mean of its divisors is an integer number (19690890).

Almost surely, 2^78677939 is an apocalyptic number.

78677939 is a deficient number, since it is larger than the sum of its proper divisors (85621).

78677939 is an equidigital number, since it uses as much as digits as its factorization.

78677939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85620.

The product of its digits is 4000752, while the sum is 56.

The square root of 78677939 is about 8870.0585680141. The cubic root of 78677939 is about 428.5001631608.

The spelling of 78677939 in words is "seventy-eight million, six hundred seventy-seven thousand, nine hundred thirty-nine".