21020102011111 has 16 divisors (see below), whose sum is σ = 24266435860480. Its totient is φ = 17834948258400.

The previous prime is 21020102011093. The next prime is 21020102011121. The reversal of 21020102011111 is 11111020102012.

It is a happy number.

It is not a de Polignac number, because 21020102011111 - 2¹¹ = 21020102009063 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21020102011091 and 21020102011100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020102011121) 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, 12304311 + ... + 13908136.

It is an arithmetic number, because the mean of its divisors is an integer number (1516652241280).

Almost surely, 2^{21020102011111} is an apocalyptic number.

21020102011111 is a deficient number, since it is larger than the sum of its proper divisors (3246333849369).

21020102011111 is a wasteful number, since it uses less digits than its factorization.

21020102011111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26213614.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21020102011111 its reverse (11111020102012), we get a palindrome (32131122113123).

The spelling of 21020102011111 in words is "twenty-one trillion, twenty billion, one hundred two million, eleven thousand, one hundred eleven".