866444205661760 has 84 divisors (see below), whose sum is σ = 2267837150591964. Its totient is φ = 315070620226560.

The previous prime is 866444205661751. The next prime is 866444205661781. The reversal of 866444205661760 is 67166502444668.

It can be written as a sum of positive squares in 2 ways, for example, as 237300961739776 + 629143243921984 = 15404576^2 + 25082728^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11188548647 + ... + 11188626086.

It is an arithmetic number, because the mean of its divisors is an integer number (26998061316571).

Almost surely, 2^{866444205661760} is an apocalyptic number.

866444205661760 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

866444205661760 is an abundant number, since it is smaller than the sum of its proper divisors (1401392944930204).

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

866444205661760 is a wasteful number, since it uses less digits than its factorization.

866444205661760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22377174772 (or 22377174751 counting only the distinct ones).

The product of its (nonzero) digits is 278691840, while the sum is 65.

The spelling of 866444205661760 in words is "eight hundred sixty-six trillion, four hundred forty-four billion, two hundred five million, six hundred sixty-one thousand, seven hundred sixty".