78731680 has 48 divisors (see below), whose sum is σ = 186810624. Its totient is φ = 31356160.

The previous prime is 78731669. The next prime is 78731683. The reversal of 78731680 is 8613787.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is not an unprimeable number, because it can be changed into a prime (78731683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41145 + ... + 43015.

It is an arithmetic number, because the mean of its divisors is an integer number (3891888).

Almost surely, 2^78731680 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78731680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (93405312).

78731680 is an abundant number, since it is smaller than the sum of its proper divisors (108078944).

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

78731680 is a wasteful number, since it uses less digits than its factorization.

78731680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2149 (or 2141 counting only the distinct ones).

The product of its (nonzero) digits is 56448, while the sum is 40.

The square root of 78731680 is about 8873.0873995470. The cubic root of 78731680 is about 428.5977033627.

The spelling of 78731680 in words is "seventy-eight million, seven hundred thirty-one thousand, six hundred eighty".