78163280 has 80 divisors (see below), whose sum is σ = 207267984. Its totient is φ = 27156480.

The previous prime is 78163249. The next prime is 78163313. The reversal of 78163280 is 8236187.

It is a Cunningham number, because it is equal to 8841²-1.

It can be written as a sum of positive squares in 8 ways, for example, as 300304 + 77862976 = 548^2 + 8824^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×78163280² = 12218996680716800, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 78163280.

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 15470 + ... + 19890.

Almost surely, 2^78163280 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 78163280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103633992).

78163280 is an abundant number, since it is smaller than the sum of its proper divisors (129104704).

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

78163280 is a wasteful number, since it uses less digits than its factorization.

78163280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4464 (or 4458 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 78163280 is about 8840.9999434453. Note that the first 4 decimals coincide. The cubic root of 78163280 is about 427.5637970063.

The spelling of 78163280 in words is "seventy-eight million, one hundred sixty-three thousand, two hundred eighty".