78128256780 has 648 divisors, whose sum is σ = 296847860400. Its totient is φ = 17200947456.

The previous prime is 78128256763. The next prime is 78128256841. The reversal of 78128256780 is 8765282187.

78128256780 is a `hidden beast` number, since 78 + 1 + 2 + 8 + 2 + 567 + 8 + 0 = 666.

It is a super-2 number, since 2×78128256780² (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 an unprimeable number.

It is a polite number, since it can be written in 215 ways as a sum of consecutive naturals, for example, 186463411 + ... + 186463829.

It is an arithmetic number, because the mean of its divisors is an integer number (458098550).

Almost surely, 2^78128256780 is an apocalyptic number.

78128256780 is a gapful number since it is divisible by the number (70) 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 78128256780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (148423930200).

78128256780 is an abundant number, since it is smaller than the sum of its proper divisors (218719603620).

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

78128256780 is a wasteful number, since it uses less digits than its factorization.

78128256780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 495 (or 465 counting only the distinct ones).

The product of its (nonzero) digits is 3010560, while the sum is 54.

The spelling of 78128256780 in words is "seventy-eight billion, one hundred twenty-eight million, two hundred fifty-six thousand, seven hundred eighty".