21011212211 has 16 divisors (see below), whose sum is σ = 23772808800. Its totient is φ = 18394924800.

The previous prime is 21011212207. The next prime is 21011212217. The reversal of 21011212211 is 11221211012.

It is a cyclic number.

It is not a de Polignac number, because 21011212211 - 2² = 21011212207 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21011212217) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39431 + ... + 208751.

It is an arithmetic number, because the mean of its divisors is an integer number (1485800550).

Almost surely, 2^21011212211 is an apocalyptic number.

21011212211 is a deficient number, since it is larger than the sum of its proper divisors (2761596589).

21011212211 is a wasteful number, since it uses less digits than its factorization.

21011212211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169750.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21011212211 its reverse (11221211012), we get a palindrome (32232423223).

The spelling of 21011212211 in words is "twenty-one billion, eleven million, two hundred twelve thousand, two hundred eleven".