21012021220211 has 16 divisors (see below), whose sum is σ = 24148270944000. Its totient is φ = 17909407745568.

The previous prime is 21012021220111. The next prime is 21012021220219. The reversal of 21012021220211 is 11202212021012.

It is a cyclic number.

It is not a de Polignac number, because 21012021220211 - 2³⁴ = 20994841351027 is a prime.

It is a super-2 number, since 2×21012021220211² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21012021220211.

It is not an unprimeable number, because it can be changed into a prime (21012021220219) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 138880841 + ... + 139032053.

It is an arithmetic number, because the mean of its divisors is an integer number (1509266934000).

Almost surely, 2^{21012021220211} is an apocalyptic number.

21012021220211 is a deficient number, since it is larger than the sum of its proper divisors (3136249723789).

21012021220211 is a wasteful number, since it uses less digits than its factorization.

21012021220211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 262298.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21012021220211 its reverse (11202212021012), we get a palindrome (32214233241223).

The spelling of 21012021220211 in words is "twenty-one trillion, twelve billion, twenty-one million, two hundred twenty thousand, two hundred eleven".