21020210101221 has 8 divisors (see below), whose sum is σ = 28027088216640. Its totient is φ = 14013402693312.

The previous prime is 21020210101201. The next prime is 21020210101223. The reversal of 21020210101221 is 12210101202012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21020210101221 - 2⁹ = 21020210100709 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21020210101221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020210101223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16979281 + ... + 18175158.

It is an arithmetic number, because the mean of its divisors is an integer number (3503386027080).

Almost surely, 2^{21020210101221} is an apocalyptic number.

It is an amenable number.

21020210101221 is a deficient number, since it is larger than the sum of its proper divisors (7006878115419).

21020210101221 is a wasteful number, since it uses less digits than its factorization.

21020210101221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35353755.

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

Adding to 21020210101221 its reverse (12210101202012), we get a palindrome (33230311303233).

The spelling of 21020210101221 in words is "twenty-one trillion, twenty billion, two hundred ten million, one hundred one thousand, two hundred twenty-one".