866788805313520 has 160 divisors (see below), whose sum is σ = 2138782312742400. Its totient is φ = 325984100293632.

The previous prime is 866788805313493. The next prime is 866788805313527. The reversal of 866788805313520 is 25313508887668.

It is a self number, because there is not a number n which added to its sum of digits gives 866788805313520.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866788805313527) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 998643886 + ... + 999511474.

It is an arithmetic number, because the mean of its divisors is an integer number (13367389454640).

Almost surely, 2^{866788805313520} is an apocalyptic number.

866788805313520 is a gapful number since it is divisible by the number (80) 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 866788805313520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1069391156371200).

866788805313520 is an abundant number, since it is smaller than the sum of its proper divisors (1271993507428880).

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

866788805313520 is a wasteful number, since it uses less digits than its factorization.

866788805313520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 876887 (or 876881 counting only the distinct ones).

The product of its (nonzero) digits is 464486400, while the sum is 70.

The spelling of 866788805313520 in words is "eight hundred sixty-six trillion, seven hundred eighty-eight billion, eight hundred five million, three hundred thirteen thousand, five hundred twenty".