21305205411 has 8 divisors (see below), whose sum is σ = 32465074944. Its totient is φ = 12174403080.

The previous prime is 21305205403. The next prime is 21305205451. The reversal of 21305205411 is 11450250312.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21305205411 - 2³ = 21305205403 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21305205451) 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 7 ways as a sum of consecutive naturals, for example, 507266775 + ... + 507266816.

It is an arithmetic number, because the mean of its divisors is an integer number (4058134368).

Almost surely, 2^21305205411 is an apocalyptic number.

21305205411 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21305205411 is a deficient number, since it is larger than the sum of its proper divisors (11159869533).

21305205411 is a wasteful number, since it uses less digits than its factorization.

21305205411 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1014533601.

The product of its (nonzero) digits is 1200, while the sum is 24.

Adding to 21305205411 its reverse (11450250312), we get a palindrome (32755455723).

The spelling of 21305205411 in words is "twenty-one billion, three hundred five million, two hundred five thousand, four hundred eleven".