21121010021211 has 4 divisors (see below), whose sum is σ = 28161346694952. Its totient is φ = 14080673347472.

The previous prime is 21121010021147. The next prime is 21121010021233. The reversal of 21121010021211 is 11212001012112.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21121010021211 - 2⁶ = 21121010021147 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21121010025211) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3520168336866 + ... + 3520168336871.

It is an arithmetic number, because the mean of its divisors is an integer number (7040336673738).

Almost surely, 2^{21121010021211} is an apocalyptic number.

21121010021211 is a deficient number, since it is larger than the sum of its proper divisors (7040336673741).

21121010021211 is an equidigital number, since it uses as much as digits as its factorization.

21121010021211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7040336673740.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21121010021211 its reverse (11212001012112), we get a palindrome (32333011033323).

Subtracting from 21121010021211 its reverse (11212001012112), we obtain a palindrome (9909009009099).

The spelling of 21121010021211 in words is "twenty-one trillion, one hundred twenty-one billion, ten million, twenty-one thousand, two hundred eleven".