21105445411 has 4 divisors (see below), whose sum is σ = 21310352752. Its totient is φ = 20900538072.

The previous prime is 21105445409. The next prime is 21105445421. The reversal of 21105445411 is 11454450112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21105445411 - 2¹ = 21105445409 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21105445411.

It is not an unprimeable number, because it can be changed into a prime (21105445421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 102453516 + ... + 102453721.

It is an arithmetic number, because the mean of its divisors is an integer number (5327588188).

Almost surely, 2^21105445411 is an apocalyptic number.

21105445411 is a deficient number, since it is larger than the sum of its proper divisors (204907341).

21105445411 is a wasteful number, since it uses less digits than its factorization.

21105445411 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204907340.

The product of its (nonzero) digits is 3200, while the sum is 28.

Adding to 21105445411 its reverse (11454450112), we get a palindrome (32559895523).

The spelling of 21105445411 in words is "twenty-one billion, one hundred five million, four hundred forty-five thousand, four hundred eleven".