21212210011211 has 16 divisors (see below), whose sum is σ = 22599092792448. Its totient is φ = 19841057308800.

The previous prime is 21212210011193. The next prime is 21212210011231. The reversal of 21212210011211 is 11211001221212.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21212210011211 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21212210011211.

It is not an unprimeable number, because it can be changed into a prime (21212210011231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1800425 + ... + 6757658.

It is an arithmetic number, because the mean of its divisors is an integer number (1412443299528).

Almost surely, 2^{21212210011211} is an apocalyptic number.

21212210011211 is a deficient number, since it is larger than the sum of its proper divisors (1386882781237).

21212210011211 is a wasteful number, since it uses less digits than its factorization.

21212210011211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8559002.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 21212210011211 its reverse (11211001221212), we get a palindrome (32423211232423).

The spelling of 21212210011211 in words is "twenty-one trillion, two hundred twelve billion, two hundred ten million, eleven thousand, two hundred eleven".