21020111012011 has 8 divisors (see below), whose sum is σ = 21536920863920. Its totient is φ = 20504572526592.

The previous prime is 21020111011919. The next prime is 21020111012077. The reversal of 21020111012011 is 11021011102012.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21020111012011 - 2⁹ = 21020111011499 is a prime.

It is a super-2 number, since 2×21020111012011² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21020111011982 and 21020111012000.

It is not an unprimeable number, because it can be changed into a prime (21020115012011) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 317808150 + ... + 317874283.

It is an arithmetic number, because the mean of its divisors is an integer number (2692115107990).

Almost surely, 2^{21020111012011} is an apocalyptic number.

21020111012011 is a deficient number, since it is larger than the sum of its proper divisors (516809851909).

21020111012011 is an equidigital number, since it uses as much as digits as its factorization.

21020111012011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 635683245.

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

Adding to 21020111012011 its reverse (11021011102012), we get a palindrome (32041122114023).

Subtracting from 21020111012011 its reverse (11021011102012), we obtain a palindrome (9999099909999).

The spelling of 21020111012011 in words is "twenty-one trillion, twenty billion, one hundred eleven million, twelve thousand, eleven".