21166281861318 has 64 divisors (see below), whose sum is σ = 51392000620800. Its totient is φ = 6404049535680.

The previous prime is 21166281861301. The next prime is 21166281861331. The reversal of 21166281861318 is 81316818266112.

21166281861318 is a `hidden beast` number, since 2 + 1 + 1 + 6 + 6 + 2 + 8 + 1 + 8 + 613 + 18 = 666.

It is a super-2 number, since 2×21166281861318² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 27326823 + ... + 28090706.

It is an arithmetic number, because the mean of its divisors is an integer number (803000009700).

Almost surely, 2^{21166281861318} is an apocalyptic number.

21166281861318 is an abundant number, since it is smaller than the sum of its proper divisors (30225718759482).

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

21166281861318 is a wasteful number, since it uses less digits than its factorization.

21166281861318 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55418194 (or 55418188 counting only the distinct ones).

The product of its digits is 1327104, while the sum is 54.

The spelling of 21166281861318 in words is "twenty-one trillion, one hundred sixty-six billion, two hundred eighty-one million, eight hundred sixty-one thousand, three hundred eighteen".