78217560368640 has 3840 divisors, whose sum is σ = 360131030138880. Its totient is φ = 15801827328000.

The previous prime is 78217560368617. The next prime is 78217560368663. The reversal of 78217560368640 is 4686306571287.

78217560368640 is a `hidden beast` number, since 7 + 8 + 2 + 1 + 7 + 560 + 3 + 6 + 8 + 64 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (78217560368617) and next prime (78217560368663).

It is a tau number, because it is divible by the number of its divisors (3840).

It is a super-2 number, since 2×78217560368640² (a number of 29 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 370699338135 + ... + 370699338345.

It is an arithmetic number, because the mean of its divisors is an integer number (93784122432).

Almost surely, 2^{78217560368640} is an apocalyptic number.

78217560368640 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 78217560368640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (180065515069440).

78217560368640 is an abundant number, since it is smaller than the sum of its proper divisors (281913469770240).

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

78217560368640 is a wasteful number, since it uses less digits than its factorization.

78217560368640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 447 (or 419 counting only the distinct ones).

The product of its (nonzero) digits is 81285120, while the sum is 63.

The spelling of 78217560368640 in words is "seventy-eight trillion, two hundred seventeen billion, five hundred sixty million, three hundred sixty-eight thousand, six hundred forty".