21111021011021 has 16 divisors (see below), whose sum is σ = 21796374234624. Its totient is φ = 20431941272064.

The previous prime is 21111021010987. The next prime is 21111021011039. The reversal of 21111021011021 is 12011012011112.

It is a cyclic number.

It is not a de Polignac number, because 21111021011021 - 2³⁰ = 21109947269197 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21111021010987 and 21111021011005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111021011621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4937180 + ... + 8160746.

It is an arithmetic number, because the mean of its divisors is an integer number (1362273389664).

Almost surely, 2^{21111021011021} is an apocalyptic number.

It is an amenable number.

21111021011021 is a deficient number, since it is larger than the sum of its proper divisors (685353223603).

21111021011021 is a wasteful number, since it uses less digits than its factorization.

21111021011021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3224540.

The product of its (nonzero) digits is 8, while the sum is 14.

Adding to 21111021011021 its reverse (12011012011112), we get a palindrome (33122033022133).

The spelling of 21111021011021 in words is "twenty-one trillion, one hundred eleven billion, twenty-one million, eleven thousand, twenty-one".