21212110100101 has 4 divisors (see below), whose sum is σ = 21292764511392. Its totient is φ = 21131455688812.

The previous prime is 21212110100017. The next prime is 21212110100119. The reversal of 21212110100101 is 10100101121212.

It is a happy number.

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 21212110100101 - 2¹⁵ = 21212110067333 is a prime.

It is a super-3 number, since 3×21212110100101³ (a number of 41 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212110100131) 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, 40327205251 + ... + 40327205776.

It is an arithmetic number, because the mean of its divisors is an integer number (5323191127848).

Almost surely, 2^{21212110100101} is an apocalyptic number.

It is an amenable number.

21212110100101 is a deficient number, since it is larger than the sum of its proper divisors (80654411291).

21212110100101 is an equidigital number, since it uses as much as digits as its factorization.

21212110100101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80654411290.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21212110100101 its reverse (10100101121212), we get a palindrome (31312211221313).

The spelling of 21212110100101 in words is "twenty-one trillion, two hundred twelve billion, one hundred ten million, one hundred thousand, one hundred one".