21010212101 has 4 divisors (see below), whose sum is σ = 21010665600. Its totient is φ = 21009758604.

The previous prime is 21010212073. The next prime is 21010212133. The reversal of 21010212101 is 10121201012.

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 a de Polignac number, because none of the positive numbers 2^k-21010212101 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 (21010217101) 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, 148181 + ... + 252938.

It is an arithmetic number, because the mean of its divisors is an integer number (5252666400).

Almost surely, 2^21010212101 is an apocalyptic number.

It is an amenable number.

21010212101 is a deficient number, since it is larger than the sum of its proper divisors (453499).

21010212101 is an equidigital number, since it uses as much as digits as its factorization.

21010212101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 453498.

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

Adding to 21010212101 its reverse (10121201012), we get a palindrome (31131413113).

The spelling of 21010212101 in words is "twenty-one billion, ten million, two hundred twelve thousand, one hundred one".