21011113101223 has 4 divisors (see below), whose sum is σ = 24012700687120. Its totient is φ = 18009525515328.

The previous prime is 21011113101137. The next prime is 21011113101233. The reversal of 21011113101223 is 32210131111012.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21011113101223 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 21011113101223.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011113101233) 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, 1500793792938 + ... + 1500793792951.

It is an arithmetic number, because the mean of its divisors is an integer number (6003175171780).

Almost surely, 2^{21011113101223} is an apocalyptic number.

21011113101223 is a deficient number, since it is larger than the sum of its proper divisors (3001587585897).

21011113101223 is an equidigital number, since it uses as much as digits as its factorization.

21011113101223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3001587585896.

The product of its (nonzero) digits is 72, while the sum is 19.

Adding to 21011113101223 its reverse (32210131111012), we get a palindrome (53221244212235).

The spelling of 21011113101223 in words is "twenty-one trillion, eleven billion, one hundred thirteen million, one hundred one thousand, two hundred twenty-three".