21210012212101 has 16 divisors (see below), whose sum is σ = 21400461558000. Its totient is φ = 21020257133568.

The previous prime is 21210012212099. The next prime is 21210012212149. The reversal of 21210012212101 is 10121221001212.

It can be written as a sum of positive squares in 8 ways, for example, as 9131426330625 + 12078585881476 = 3021825^2 + 3475426^2 .

It is not a de Polignac number, because 21210012212101 - 2¹ = 21210012212099 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210012212171) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 119733271 + ... + 119910283.

It is an arithmetic number, because the mean of its divisors is an integer number (1337528847375).

Almost surely, 2^{21210012212101} is an apocalyptic number.

It is an amenable number.

21210012212101 is a deficient number, since it is larger than the sum of its proper divisors (190449345899).

21210012212101 is a wasteful number, since it uses less digits than its factorization.

21210012212101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178968.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21210012212101 its reverse (10121221001212), we get a palindrome (31331233213313).

The spelling of 21210012212101 in words is "twenty-one trillion, two hundred ten billion, twelve million, two hundred twelve thousand, one hundred one".