11855645280 has 144 divisors (see below), whose sum is σ = 41444361504. Its totient is φ = 3084380160.

The previous prime is 11855645173. The next prime is 11855645323. The reversal of 11855645280 is 8254655811.

11855645280 is a `hidden beast` number, since 1 + 1 + 8 + 5 + 564 + 5 + 2 + 80 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 41364 + ... + 159443.

It is an arithmetic number, because the mean of its divisors is an integer number (287808066).

Almost surely, 2^11855645280 is an apocalyptic number.

11855645280 is a gapful number since it is divisible by the number (10) 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 11855645280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20722180752).

11855645280 is an abundant number, since it is smaller than the sum of its proper divisors (29588716224).

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

11855645280 is a wasteful number, since it uses less digits than its factorization.

11855645280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 200869 (or 200858 counting only the distinct ones).

The product of its (nonzero) digits is 384000, while the sum is 45.

It can be divided in two parts, 1185 and 5645280, that added together give a palindrome (5646465).

The spelling of 11855645280 in words is "eleven billion, eight hundred fifty-five million, six hundred forty-five thousand, two hundred eighty".