21102120223 has 4 divisors (see below), whose sum is σ = 21103047720. Its totient is φ = 21101192728.

The previous prime is 21102120209. The next prime is 21102120257. The reversal of 21102120223 is 32202120112.

It is a happy number.

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 21102120223 - 2²¹ = 21100023071 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21102120197 and 21102120206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21102120283) 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, 428740 + ... + 475417.

It is an arithmetic number, because the mean of its divisors is an integer number (5275761930).

Almost surely, 2^21102120223 is an apocalyptic number.

21102120223 is a deficient number, since it is larger than the sum of its proper divisors (927497).

21102120223 is an equidigital number, since it uses as much as digits as its factorization.

21102120223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 927496.

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 21102120223 its reverse (32202120112), we get a palindrome (53304240335).

The spelling of 21102120223 in words is "twenty-one billion, one hundred two million, one hundred twenty thousand, two hundred twenty-three".