78987678 has 128 divisors (see below), whose sum is σ = 212751360. Its totient is φ = 18923520.

The previous prime is 78987673. The next prime is 78987691. The reversal of 78987678 is 87678987.

78987678 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

It is an alternating number because its digits alternate between odd and even.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78987673) 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 63 ways as a sum of consecutive naturals, for example, 698950 + ... + 699062.

It is an arithmetic number, because the mean of its divisors is an integer number (1662120).

Almost surely, 2^78987678 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78987678, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (106375680).

78987678 is an abundant number, since it is smaller than the sum of its proper divisors (133763682).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78987678 is a wasteful number, since it uses less digits than its factorization.

78987678 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242.

The product of its digits is 9483264, while the sum is 60.

The square root of 78987678 is about 8887.5012236286. The cubic root of 78987678 is about 429.0617327934.

It can be divided in two parts, 7898 and 7678, that added together give a triangular number (15576 = T₁₇₆).

The spelling of 78987678 in words is "seventy-eight million, nine hundred eighty-seven thousand, six hundred seventy-eight".