21111456366 has 288 divisors, whose sum is σ = 64031647680. Its totient is φ = 4885816320.

The previous prime is 21111456323. The next prime is 21111456367. The reversal of 21111456366 is 66365411112.

21111456366 is a `hidden beast` number, since 2 + 1 + 1 + 1 + 14 + 5 + 636 + 6 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 21111456366.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111456367) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 5745906 + ... + 5749578.

It is an arithmetic number, because the mean of its divisors is an integer number (222332110).

Almost surely, 2^21111456366 is an apocalyptic number.

21111456366 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21111456366, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32015823840).

21111456366 is an abundant number, since it is smaller than the sum of its proper divisors (42920191314).

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

21111456366 is a wasteful number, since it uses less digits than its factorization.

21111456366 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3752 (or 3738 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

Adding to 21111456366 its reverse (66365411112), we get a palindrome (87476867478).

The spelling of 21111456366 in words is "twenty-one billion, one hundred eleven million, four hundred fifty-six thousand, three hundred sixty-six".