21210120010021 has 8 divisors (see below), whose sum is σ = 21373116695840. Its totient is φ = 21047271980112.

The previous prime is 21210120009931. The next prime is 21210120010081. The reversal of 21210120010021 is 12001002101212.

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 21210120010021 - 2⁹ = 21210120009509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21210120009983 and 21210120010010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210120010081) 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 7 ways as a sum of consecutive naturals, for example, 36877515 + ... + 37448248.

It is an arithmetic number, because the mean of its divisors is an integer number (2671639586980).

Almost surely, 2^{21210120010021} is an apocalyptic number.

It is an amenable number.

21210120010021 is a deficient number, since it is larger than the sum of its proper divisors (162996685819).

21210120010021 is a wasteful number, since it uses less digits than its factorization.

21210120010021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74327955.

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

Adding to 21210120010021 its reverse (12001002101212), we get a palindrome (33211122111233).

The spelling of 21210120010021 in words is "twenty-one trillion, two hundred ten billion, one hundred twenty million, ten thousand, twenty-one".