21021210001021 has 4 divisors (see below), whose sum is σ = 21021441850432. Its totient is φ = 21020978151612.

The previous prime is 21021210001019. The next prime is 21021210001061. The reversal of 21021210001021 is 12010001212012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21021210001021 - 2¹ = 21021210001019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21021210000992 and 21021210001010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021210001061) 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, 115788651 + ... + 115970056.

It is an arithmetic number, because the mean of its divisors is an integer number (5255360462608).

Almost surely, 2^{21021210001021} is an apocalyptic number.

It is an amenable number.

21021210001021 is a deficient number, since it is larger than the sum of its proper divisors (231849411).

21021210001021 is an equidigital number, since it uses as much as digits as its factorization.

21021210001021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 231849410.

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

Adding to 21021210001021 its reverse (12010001212012), we get a palindrome (33031211213033).

The spelling of 21021210001021 in words is "twenty-one trillion, twenty-one billion, two hundred ten million, one thousand, twenty-one".