78678911 has 4 divisors (see below), whose sum is σ = 78754824. Its totient is φ = 78603000.

The previous prime is 78678869. The next prime is 78678917. The reversal of 78678911 is 11987687.

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 78678911 - 2²² = 74484607 is a prime.

It is a super-2 number, since 2×78678911² = 12380742072291842, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78678917) 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, 36380 + ... + 38481.

It is an arithmetic number, because the mean of its divisors is an integer number (19688706).

Almost surely, 2^78678911 is an apocalyptic number.

78678911 is a deficient number, since it is larger than the sum of its proper divisors (75913).

78678911 is a wasteful number, since it uses less digits than its factorization.

78678911 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75912.

The product of its digits is 169344, while the sum is 47.

The square root of 78678911 is about 8870.1133589149. The cubic root of 78678911 is about 428.5019277403.

It can be divided in two parts, 786 and 78911, that added together give a palindrome (79697).

The spelling of 78678911 in words is "seventy-eight million, six hundred seventy-eight thousand, nine hundred eleven".