78391296 has 72 divisors (see below), whose sum is σ = 226461690. Its totient is φ = 26124288.

The previous prime is 78391249. The next prime is 78391297. The reversal of 78391296 is 69219387.

It can be written as a sum of positive squares in only one way, i.e., 76317696 + 2073600 = 8736^2 + 1440^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a super-2 number, since 2×78391296² = 12290390577119232, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78391297) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 16306 + ... + 20558.

Almost surely, 2^78391296 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 78391296, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113230845).

78391296 is an abundant number, since it is smaller than the sum of its proper divisors (148070394).

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

78391296 is a wasteful number, since it uses less digits than its factorization.

78391296 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4281 (or 4258 counting only the distinct ones).

The product of its digits is 163296, while the sum is 45.

The square root of 78391296 is about 8853.8859265297. The cubic root of 78391296 is about 427.9791529136.

It can be divided in two parts, 78391 and 296, that added together give a palindrome (78687).

The spelling of 78391296 in words is "seventy-eight million, three hundred ninety-one thousand, two hundred ninety-six".