78331392 has 120 divisors (see below), whose sum is σ = 229806720. Its totient is φ = 25681920.

The previous prime is 78331391. The next prime is 78331411. The reversal of 78331392 is 29313387.

It is a happy number.

It is a super-2 number, since 2×78331392² = 12271613945315328, which contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78331391) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 410017 + ... + 410207.

It is an arithmetic number, because the mean of its divisors is an integer number (1915056).

Almost surely, 2^78331392 is an apocalyptic number.

78331392 is a gapful number since it is divisible by the number (72) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78331392, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114903360).

78331392 is an abundant number, since it is smaller than the sum of its proper divisors (151475328).

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

78331392 is a wasteful number, since it uses less digits than its factorization.

78331392 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 304 (or 285 counting only the distinct ones).

The product of its digits is 27216, while the sum is 36.

The square root of 78331392 is about 8850.5023586235. The cubic root of 78331392 is about 427.8701093601.

The spelling of 78331392 in words is "seventy-eight million, three hundred thirty-one thousand, three hundred ninety-two".