21020013111111 has 16 divisors (see below), whose sum is σ = 32711996089344. Its totient is φ = 11755873593504.

The previous prime is 21020013111107. The next prime is 21020013111233. The reversal of 21020013111111 is 11111131002012.

It is not a de Polignac number, because 21020013111111 - 2² = 21020013111107 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020013111011) 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, 10648435240 + ... + 10648437213.

It is an arithmetic number, because the mean of its divisors is an integer number (2044499755584).

Almost surely, 2^{21020013111111} is an apocalyptic number.

21020013111111 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21020013111111 is a deficient number, since it is larger than the sum of its proper divisors (11691982978233).

21020013111111 is a wasteful number, since it uses less digits than its factorization.

21020013111111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21296872510.

The product of its (nonzero) digits is 12, while the sum is 15.

Adding to 21020013111111 its reverse (11111131002012), we get a palindrome (32131144113123).

The spelling of 21020013111111 in words is "twenty-one trillion, twenty billion, thirteen million, one hundred eleven thousand, one hundred eleven".