21211202005 has 16 divisors (see below), whose sum is σ = 30800805120. Its totient is φ = 13689245952.

The previous prime is 21211201987. The next prime is 21211202099. The reversal of 21211202005 is 50020211212.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21211202005 - 2¹³ = 21211193813 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21211202005.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17823945 + ... + 17825134.

It is an arithmetic number, because the mean of its divisors is an integer number (1925050320).

Almost surely, 2^21211202005 is an apocalyptic number.

It is an amenable number.

21211202005 is a deficient number, since it is larger than the sum of its proper divisors (9589603115).

21211202005 is a wasteful number, since it uses less digits than its factorization.

21211202005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35649108.

The product of its (nonzero) digits is 80, while the sum is 16.

Adding to 21211202005 its reverse (50020211212), we get a palindrome (71231413217).

The spelling of 21211202005 in words is "twenty-one billion, two hundred eleven million, two hundred two thousand, five".