21120101020021 has 16 divisors (see below), whose sum is σ = 22082833022976. Its totient is φ = 20176592670000.

The previous prime is 21120101019991. The next prime is 21120101020069. The reversal of 21120101020021 is 12002010102112.

It is a cyclic number.

It is not a de Polignac number, because 21120101020021 - 2¹⁹ = 21120100495733 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21120101019983 and 21120101020010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120101029021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12838785 + ... + 14390086.

It is an arithmetic number, because the mean of its divisors is an integer number (1380177063936).

Almost surely, 2^{21120101020021} is an apocalyptic number.

It is an amenable number.

21120101020021 is a deficient number, since it is larger than the sum of its proper divisors (962732002955).

21120101020021 is a wasteful number, since it uses less digits than its factorization.

21120101020021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27229224.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21120101020021 its reverse (12002010102112), we get a palindrome (33122111122133).

The spelling of 21120101020021 in words is "twenty-one trillion, one hundred twenty billion, one hundred one million, twenty thousand, twenty-one".