21211212122101 has 4 divisors (see below), whose sum is σ = 21219071040000. Its totient is φ = 21203353204204.

The previous prime is 21211212122081. The next prime is 21211212122117. The reversal of 21211212122101 is 10122121211212.

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 21211212122101 - 2¹⁷ = 21211211991029 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 (21211212126101) 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, 3929454901 + ... + 3929460298.

It is an arithmetic number, because the mean of its divisors is an integer number (5304767760000).

Almost surely, 2^{21211212122101} is an apocalyptic number.

It is an amenable number.

21211212122101 is a deficient number, since it is larger than the sum of its proper divisors (7858917899).

21211212122101 is an equidigital number, since it uses as much as digits as its factorization.

21211212122101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7858917898.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 21211212122101 its reverse (10122121211212), we get a palindrome (31333333333313).

The spelling of 21211212122101 in words is "twenty-one trillion, two hundred eleven billion, two hundred twelve million, one hundred twenty-two thousand, one hundred one".