21021000000011 has 4 divisors (see below), whose sum is σ = 22932000000024. Its totient is φ = 19110000000000.

The previous prime is 21021000000001. The next prime is 21021000000047. The reversal of 21021000000011 is 11000000012012.

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 21021000000011 - 2³⁰ = 21019926258187 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21021000000001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 955499999990 + ... + 955500000011.

It is an arithmetic number, because the mean of its divisors is an integer number (5733000000006).

Almost surely, 2^{21021000000011} is an apocalyptic number.

21021000000011 is a deficient number, since it is larger than the sum of its proper divisors (1911000000013).

21021000000011 is a wasteful number, since it uses less digits than its factorization.

21021000000011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1911000000012.

The product of its (nonzero) digits is 4, while the sum is 8.

Adding to 21021000000011 its reverse (11000000012012), we get a palindrome (32021000012023).

The spelling of 21021000000011 in words is "twenty-one trillion, twenty-one billion, eleven", and thus it is an aban number and an uban number.