21405022211 has 8 divisors (see below), whose sum is σ = 21464979744. Its totient is φ = 21345122880.

The previous prime is 21405022193. The next prime is 21405022237. The reversal of 21405022211 is 11222050412.

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

It is a cyclic number.

It is not a de Polignac number, because 21405022211 - 2¹⁸ = 21404760067 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21405022291) 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, 782186 + ... + 809088.

It is an arithmetic number, because the mean of its divisors is an integer number (2683122468).

Almost surely, 2^21405022211 is an apocalyptic number.

21405022211 is a deficient number, since it is larger than the sum of its proper divisors (59957533).

21405022211 is a wasteful number, since it uses less digits than its factorization.

21405022211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29101.

The product of its (nonzero) digits is 320, while the sum is 20.

Adding to 21405022211 its reverse (11222050412), we get a palindrome (32627072623).

The spelling of 21405022211 in words is "twenty-one billion, four hundred five million, twenty-two thousand, two hundred eleven".