21210120101 has 4 divisors (see below), whose sum is σ = 21703378752. Its totient is φ = 20716861452.

The previous prime is 21210120049. The next prime is 21210120103. The reversal of 21210120101 is 10102101212.

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 21210120101 - 2⁶ = 21210120037 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 (21210120103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 246629261 + ... + 246629346.

It is an arithmetic number, because the mean of its divisors is an integer number (5425844688).

Almost surely, 2^21210120101 is an apocalyptic number.

It is an amenable number.

21210120101 is a deficient number, since it is larger than the sum of its proper divisors (493258651).

21210120101 is an equidigital number, since it uses as much as digits as its factorization.

21210120101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 493258650.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21210120101 its reverse (10102101212), we get a palindrome (31312221313).

The spelling of 21210120101 in words is "twenty-one billion, two hundred ten million, one hundred twenty thousand, one hundred one".