21020101221021 has 32 divisors (see below), whose sum is σ = 33961954959360. Its totient is φ = 11289205122816.

The previous prime is 21020101220983. The next prime is 21020101221047. The reversal of 21020101221021 is 12012210102012.

It is not a de Polignac number, because 21020101221021 - 2⁶ = 21020101220957 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020101221061) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 40688961 + ... + 41202326.

It is an arithmetic number, because the mean of its divisors is an integer number (1061311092480).

Almost surely, 2^{21020101221021} is an apocalyptic number.

21020101221021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21020101221021 is a deficient number, since it is larger than the sum of its proper divisors (12941853738339).

21020101221021 is a wasteful number, since it uses less digits than its factorization.

21020101221021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81892033.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21020101221021 its reverse (12012210102012), we get a palindrome (33032311323033).

The spelling of 21020101221021 in words is "twenty-one trillion, twenty billion, one hundred one million, two hundred twenty-one thousand, twenty-one".