78637680 has 120 divisors (see below), whose sum is σ = 288128880. Its totient is φ = 19061760.

The previous prime is 78637673. The next prime is 78637681. The reversal of 78637680 is 8673687.

78637680 is a `hidden beast` number, since 7 + 8 + 637 + 6 + 8 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78637681) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2956 + ... + 12884.

It is an arithmetic number, because the mean of its divisors is an integer number (2401074).

Almost surely, 2^78637680 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 78637680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (144064440).

78637680 is an abundant number, since it is smaller than the sum of its proper divisors (209491200).

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

78637680 is a wasteful number, since it uses less digits than its factorization.

78637680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9959 (or 9950 counting only the distinct ones).

The product of its (nonzero) digits is 338688, while the sum is 45.

The square root of 78637680 is about 8867.7889014117. The cubic root of 78637680 is about 428.4270637569.

The spelling of 78637680 in words is "seventy-eight million, six hundred thirty-seven thousand, six hundred eighty".