11881281555 has 256 divisors, whose sum is σ = 26946017280. Its totient is φ = 4877107200.

The previous prime is 11881281553. The next prime is 11881281569. The reversal of 11881281555 is 55518218811.

11881281555 is a `hidden beast` number, since 1 + 1 + 8 + 8 + 12 + 81 + 555 = 666.

Together with 15064735724 it forms a betrothed pair.

It is not a de Polignac number, because 11881281555 - 2¹ = 11881281553 is a prime.

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

It is a self number, because there is not a number n which added to its sum of digits gives 11881281555.

It is not an unprimeable number, because it can be changed into a prime (11881281553) by changing a digit.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 13455144 + ... + 13456026.

It is an arithmetic number, because the mean of its divisors is an integer number (105257880).

Almost surely, 2^11881281555 is an apocalyptic number.

11881281555 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

11881281555 is an abundant number, since it is smaller than the sum of its proper divisors (15064735725).

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

11881281555 is a wasteful number, since it uses less digits than its factorization.

11881281555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 979 (or 973 counting only the distinct ones).

The product of its digits is 128000, while the sum is 45.

The spelling of 11881281555 in words is "eleven billion, eight hundred eighty-one million, two hundred eighty-one thousand, five hundred fifty-five".