78730128 has 120 divisors (see below), whose sum is σ = 241558200. Its totient is φ = 23826432.

The previous prime is 78730109. The next prime is 78730133. The reversal of 78730128 is 82103787.

It is a Cunningham number, because it is equal to 8873²-1.

It can be written as a sum of positive squares in 4 ways, for example, as 3873024 + 74857104 = 1968^2 + 8652^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 78730092 and 78730101.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 70438 + ... + 71546.

It is an arithmetic number, because the mean of its divisors is an integer number (2012985).

Almost surely, 2^78730128 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 78730128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120779100).

78730128 is an abundant number, since it is smaller than the sum of its proper divisors (162828072).

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

78730128 is a wasteful number, since it uses less digits than its factorization.

78730128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1169 (or 1160 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 36.

The square root of 78730128 is about 8872.9999436493. Note that the first 4 decimals coincide. The cubic root of 78730128 is about 428.5948870969.

The spelling of 78730128 in words is "seventy-eight million, seven hundred thirty thousand, one hundred twenty-eight".