78389312 has 56 divisors (see below), whose sum is σ = 166466520. Its totient is φ = 36495360.

The previous prime is 78389303. The next prime is 78389321. The reversal of 78389312 is 21398387.

It is an interprime number because it is at equal distance from previous prime (78389303) and next prime (78389321).

It can be written as a sum of positive squares in 4 ways, for example, as 40246336 + 38142976 = 6344^2 + 6176^2 .

It is a super-2 number, since 2×78389312² = 12289768471666688, 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 78389312.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 118262 + ... + 118922.

Almost surely, 2^78389312 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 78389312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (83233260).

78389312 is an abundant number, since it is smaller than the sum of its proper divisors (88077208).

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

78389312 is a wasteful number, since it uses less digits than its factorization.

78389312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 799 (or 789 counting only the distinct ones).

The product of its digits is 72576, while the sum is 41.

The square root of 78389312 is about 8853.7738846212. The cubic root of 78389312 is about 427.9755423180.

The spelling of 78389312 in words is "seventy-eight million, three hundred eighty-nine thousand, three hundred twelve".