21012020100011 has 4 divisors (see below), whose sum is σ = 21039777062592. Its totient is φ = 20984263137432.

The previous prime is 21012020100007. The next prime is 21012020100077. The reversal of 21012020100011 is 11000102021012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21012020100011 - 2² = 21012020100007 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21012020099965 and 21012020100001.

It is not an unprimeable number, because it can be changed into a prime (21012020100811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13878480155 + ... + 13878481668.

It is an arithmetic number, because the mean of its divisors is an integer number (5259944265648).

Almost surely, 2^{21012020100011} is an apocalyptic number.

21012020100011 is a deficient number, since it is larger than the sum of its proper divisors (27756962581).

21012020100011 is an equidigital number, since it uses as much as digits as its factorization.

21012020100011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27756962580.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21012020100011 its reverse (11000102021012), we get a palindrome (32012122121023).

The spelling of 21012020100011 in words is "twenty-one trillion, twelve billion, twenty million, one hundred thousand, eleven".