856995438780 has 576 divisors, whose sum is σ = 2921760616320. Its totient is φ = 201989578752.

The previous prime is 856995438779. The next prime is 856995438809. The reversal of 856995438780 is 87834599658.

856995438780 is a `hidden beast` number, since 8 + 5 + 6 + 9 + 9 + 543 + 8 + 78 + 0 = 666.

It is a Smith number, since the sum of its digits (72) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 856995438699 and 856995438708.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 1265871802 + ... + 1265872478.

It is an arithmetic number, because the mean of its divisors is an integer number (5072501070).

Almost surely, 2^856995438780 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 856995438780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1460880308160).

856995438780 is an abundant number, since it is smaller than the sum of its proper divisors (2064765177540).

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

856995438780 is a wasteful number, since it uses less digits than its factorization.

856995438780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 990 (or 985 counting only the distinct ones).

The product of its (nonzero) digits is 522547200, while the sum is 72.

The spelling of 856995438780 in words is "eight hundred fifty-six billion, nine hundred ninety-five million, four hundred thirty-eight thousand, seven hundred eighty".