21201212101211 has 8 divisors (see below), whose sum is σ = 22019386727424. Its totient is φ = 20391429009960.

The previous prime is 21201212101169. The next prime is 21201212101213. The reversal of 21201212101211 is 11210121210212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21201212101211 is a prime.

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 21201212101211.

It is not an unprimeable number, because it can be changed into a prime (21201212101213) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2097878591 + ... + 2097888696.

It is an arithmetic number, because the mean of its divisors is an integer number (2752423340928).

Almost surely, 2^{21201212101211} is an apocalyptic number.

21201212101211 is a deficient number, since it is larger than the sum of its proper divisors (818174626213).

21201212101211 is a wasteful number, since it uses less digits than its factorization.

21201212101211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4195767481.

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

Adding to 21201212101211 its reverse (11210121210212), we get a palindrome (32411333311423).

The spelling of 21201212101211 in words is "twenty-one trillion, two hundred one billion, two hundred twelve million, one hundred one thousand, two hundred eleven".