71778786816 has 320 divisors, whose sum is σ = 220413321216. Its totient is φ = 20553523200.

The previous prime is 71778786799. The next prime is 71778786841. The reversal of 71778786816 is 61868787717.

It is a Harshad number since it is a multiple of its sum of digits (66).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 22520775 + ... + 22523961.

Almost surely, 2^71778786816 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 71778786816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110206660608).

71778786816 is an abundant number, since it is smaller than the sum of its proper divisors (148634534400).

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

71778786816 is a wasteful number, since it uses less digits than its factorization.

71778786816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3293 (or 3277 counting only the distinct ones).

The product of its digits is 44255232, while the sum is 66.

Subtracting from 71778786816 its reverse (61868787717), we obtain a palindrome (9909999099).

The spelling of 71778786816 in words is "seventy-one billion, seven hundred seventy-eight million, seven hundred eighty-six thousand, eight hundred sixteen".