78384320784 has 675 divisors, whose sum is σ = 292979518293. Its totient is φ = 20157984000.

The previous prime is 78384320771. The next prime is 78384320801. The reversal of 78384320784 is 48702348387.

The square root of 78384320784 is 279972.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 75310727184 + 3073593600 = 274428^2 + 55440^2 .

It is a super-2 number, since 2×78384320784² (a number of 23 digits) contains 22 as substring.

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

It is a self number, because there is not a number n which added to its sum of digits gives 78384320784.

It is an unprimeable number.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 776082334 + ... + 776082434.

Almost surely, 2^78384320784 is an apocalyptic number.

78384320784 is the 279972-nd square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78384320784

78384320784 is an abundant number, since it is smaller than the sum of its proper divisors (214595197509).

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

78384320784 is a wasteful number, since it uses less digits than its factorization.

78384320784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 258 (or 124 counting only the distinct ones).

The product of its (nonzero) digits is 7225344, while the sum is 54.

The spelling of 78384320784 in words is "seventy-eight billion, three hundred eighty-four million, three hundred twenty thousand, seven hundred eighty-four".