78218866817312 has 96 divisors (see below), whose sum is σ = 167314204713600. Its totient is φ = 35780970700800.

The previous prime is 78218866817293. The next prime is 78218866817317. The reversal of 78218866817312 is 21371866881287.

It is a happy number.

It is a super-2 number, since 2×78218866817312² (a number of 29 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78218866817317) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26422064 + ... + 29232912.

It is an arithmetic number, because the mean of its divisors is an integer number (1742856299100).

Almost surely, 2^{78218866817312} 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 78218866817312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (83657102356800).

78218866817312 is an abundant number, since it is smaller than the sum of its proper divisors (89095337896288).

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

78218866817312 is a wasteful number, since it uses less digits than its factorization.

78218866817312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2811466 (or 2811458 counting only the distinct ones).

The product of its digits is 86704128, while the sum is 68.

The spelling of 78218866817312 in words is "seventy-eight trillion, two hundred eighteen billion, eight hundred sixty-six million, eight hundred seventeen thousand, three hundred twelve".