21201220202011 has 4 divisors (see below), whose sum is σ = 21215477917152. Its totient is φ = 21186962486872.

The previous prime is 21201220202009. The next prime is 21201220202047. The reversal of 21201220202011 is 11020202210212.

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 21201220202011 - 2¹ = 21201220202009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21201220202081) 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, 7128855340 + ... + 7128858313.

It is an arithmetic number, because the mean of its divisors is an integer number (5303869479288).

Almost surely, 2^{21201220202011} is an apocalyptic number.

21201220202011 is a deficient number, since it is larger than the sum of its proper divisors (14257715141).

21201220202011 is a wasteful number, since it uses less digits than its factorization.

21201220202011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14257715140.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21201220202011 its reverse (11020202210212), we get a palindrome (32221422412223).

The spelling of 21201220202011 in words is "twenty-one trillion, two hundred one billion, two hundred twenty million, two hundred two thousand, eleven".