21105104011 has 4 divisors (see below), whose sum is σ = 21223009800. Its totient is φ = 20987198224.

The previous prime is 21105103997. The next prime is 21105104023. The reversal of 21105104011 is 11040150112.

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 21105104011 - 2⁵ = 21105103979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21105104071) 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, 58952626 + ... + 58952983.

It is an arithmetic number, because the mean of its divisors is an integer number (5305752450).

Almost surely, 2^21105104011 is an apocalyptic number.

21105104011 is a deficient number, since it is larger than the sum of its proper divisors (117905789).

21105104011 is a wasteful number, since it uses less digits than its factorization.

21105104011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117905788.

The product of its (nonzero) digits is 40, while the sum is 16.

Adding to 21105104011 its reverse (11040150112), we get a palindrome (32145254123).

The spelling of 21105104011 in words is "twenty-one billion, one hundred five million, one hundred four thousand, eleven".