21010101223 has 4 divisors (see below), whose sum is σ = 21037710528. Its totient is φ = 20982491920.

The previous prime is 21010101209. The next prime is 21010101241. The reversal of 21010101223 is 32210101012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21010101223 - 2⁵ = 21010101191 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 (21010101283) 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, 13803511 + ... + 13805032.

It is an arithmetic number, because the mean of its divisors is an integer number (5259427632).

Almost surely, 2^21010101223 is an apocalyptic number.

21010101223 is a deficient number, since it is larger than the sum of its proper divisors (27609305).

21010101223 is an equidigital number, since it uses as much as digits as its factorization.

21010101223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27609304.

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 21010101223 its reverse (32210101012), we get a palindrome (53220202235).

The spelling of 21010101223 in words is "twenty-one billion, ten million, one hundred one thousand, two hundred twenty-three".