21212202210101 has 4 divisors (see below), whose sum is σ = 24242516811552. Its totient is φ = 18181887608652.

The previous prime is 21212202210083. The next prime is 21212202210103. The reversal of 21212202210101 is 10101220221212.

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 21212202210101 - 2³⁸ = 20937324303157 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21212202210101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212202210103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1515157300715 + ... + 1515157300728.

It is an arithmetic number, because the mean of its divisors is an integer number (6060629202888).

Almost surely, 2^{21212202210101} is an apocalyptic number.

It is an amenable number.

21212202210101 is a deficient number, since it is larger than the sum of its proper divisors (3030314601451).

21212202210101 is an equidigital number, since it uses as much as digits as its factorization.

21212202210101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3030314601450.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21212202210101 its reverse (10101220221212), we get a palindrome (31313422431313).

The spelling of 21212202210101 in words is "twenty-one trillion, two hundred twelve billion, two hundred two million, two hundred ten thousand, one hundred one".