78685992 has 320 divisors, whose sum is σ = 292723200. Its totient is φ = 19128960.

The previous prime is 78685991. The next prime is 78686021. The reversal of 78685992 is 29958687.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78685991) 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 79 ways as a sum of consecutive naturals, for example, 947983 + ... + 948065.

It is an arithmetic number, because the mean of its divisors is an integer number (914760).

Almost surely, 2^78685992 is an apocalyptic number.

78685992 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 78685992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (146361600).

78685992 is an abundant number, since it is smaller than the sum of its proper divisors (214037208).

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

78685992 is a wasteful number, since it uses less digits than its factorization.

78685992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138 (or 125 counting only the distinct ones).

The product of its digits is 2177280, while the sum is 54.

The square root of 78685992 is about 8870.5124992866. The cubic root of 78685992 is about 428.5147822274.

The spelling of 78685992 in words is "seventy-eight million, six hundred eighty-five thousand, nine hundred ninety-two".