78423234577920 has 720 divisors, whose sum is σ = 288713890436400. Its totient is φ = 19669339865088.

The previous prime is 78423234577913. The next prime is 78423234577921. The reversal of 78423234577920 is 2977543232487.

It is a happy number.

78423234577920 is a `hidden beast` number, since 7 + 8 + 4 + 2 + 3 + 2 + 34 + 577 + 9 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (720).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78423234577921) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 12977530419 + ... + 12977536461.

It is an arithmetic number, because the mean of its divisors is an integer number (400991514495).

Almost surely, 2^{78423234577920} 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 78423234577920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (144356945218200).

78423234577920 is an abundant number, since it is smaller than the sum of its proper divisors (210290655858480).

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

78423234577920 is a wasteful number, since it uses less digits than its factorization.

78423234577920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8055 (or 8019 counting only the distinct ones).

The product of its (nonzero) digits is 142248960, while the sum is 63.

The spelling of 78423234577920 in words is "seventy-eight trillion, four hundred twenty-three billion, two hundred thirty-four million, five hundred seventy-seven thousand, nine hundred twenty".