21020011111211 has 16 divisors (see below), whose sum is σ = 24039618984384. Its totient is φ = 18004594443264.

The previous prime is 21020011111201. The next prime is 21020011111217. The reversal of 21020011111211 is 11211111002012.

It is a cyclic number.

It is not a de Polignac number, because 21020011111211 - 2¹⁴ = 21020011094827 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21020011111217) 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, 65504291 + ... + 65824403.

It is an arithmetic number, because the mean of its divisors is an integer number (1502476186524).

Almost surely, 2^{21020011111211} is an apocalyptic number.

21020011111211 is a deficient number, since it is larger than the sum of its proper divisors (3019607873173).

21020011111211 is a wasteful number, since it uses less digits than its factorization.

21020011111211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 326630.

The product of its (nonzero) digits is 8, while the sum is 14.

Adding to 21020011111211 its reverse (11211111002012), we get a palindrome (32231122113223).

The spelling of 21020011111211 in words is "twenty-one trillion, twenty billion, eleven million, one hundred eleven thousand, two hundred eleven".