21211020001021 has 8 divisors (see below), whose sum is σ = 21619814584824. Its totient is φ = 20804195512320.

The previous prime is 21211020001019. The next prime is 21211020001027. The reversal of 21211020001021 is 12010002011212.

It can be written as a sum of positive squares in 4 ways, for example, as 2404391372100 + 18806628628921 = 1550610^2 + 4336661^2 .

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 21211020001021 - 2¹ = 21211020001019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21211020000992 and 21211020001010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211020001027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 492502036 + ... + 492545101.

It is an arithmetic number, because the mean of its divisors is an integer number (2702476823103).

Almost surely, 2^{21211020001021} is an apocalyptic number.

It is an amenable number.

21211020001021 is a deficient number, since it is larger than the sum of its proper divisors (408794583803).

21211020001021 is an equidigital number, since it uses as much as digits as its factorization.

21211020001021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 985047551.

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

Adding to 21211020001021 its reverse (12010002011212), we get a palindrome (33221022012233).

The spelling of 21211020001021 in words is "twenty-one trillion, two hundred eleven billion, twenty million, one thousand, twenty-one".