212870666778 has 96 divisors (see below), whose sum is σ = 540936092160. Its totient is φ = 55223209440.

The previous prime is 212870666753. The next prime is 212870666821. The reversal of 212870666778 is 877666078212.

It is a happy number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2621593 + ... + 2701571.

It is an arithmetic number, because the mean of its divisors is an integer number (5634750960).

Almost surely, 2^212870666778 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 212870666778, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (270468046080).

212870666778 is an abundant number, since it is smaller than the sum of its proper divisors (328065425382).

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

212870666778 is a wasteful number, since it uses less digits than its factorization.

212870666778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80832 (or 80825 counting only the distinct ones).

The product of its (nonzero) digits is 18966528, while the sum is 60.

The spelling of 212870666778 in words is "two hundred twelve billion, eight hundred seventy million, six hundred sixty-six thousand, seven hundred seventy-eight".