21012102120211 has 4 divisors (see below), whose sum is σ = 21012117550632. Its totient is φ = 21012086689792.

The previous prime is 21012102120199. The next prime is 21012102120391. The reversal of 21012102120211 is 11202120121012.

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 21012102120211 - 2²¹ = 21012100023059 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21012102120011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5451145 + ... + 8469898.

It is an arithmetic number, because the mean of its divisors is an integer number (5253029387658).

Almost surely, 2^{21012102120211} is an apocalyptic number.

21012102120211 is a deficient number, since it is larger than the sum of its proper divisors (15430421).

21012102120211 is a wasteful number, since it uses less digits than its factorization.

21012102120211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15430420.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21012102120211 its reverse (11202120121012), we get a palindrome (32214222241223).

The spelling of 21012102120211 in words is "twenty-one trillion, twelve billion, one hundred two million, one hundred twenty thousand, two hundred eleven".