21011012223 has 4 divisors (see below), whose sum is σ = 28014682968. Its totient is φ = 14007341480.

The previous prime is 21011012177. The next prime is 21011012273. The reversal of 21011012223 is 32221011012.

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 21011012223 - 2⁶ = 21011012159 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011012273) 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, 3501835368 + ... + 3501835373.

It is an arithmetic number, because the mean of its divisors is an integer number (7003670742).

Almost surely, 2^21011012223 is an apocalyptic number.

21011012223 is a deficient number, since it is larger than the sum of its proper divisors (7003670745).

21011012223 is an equidigital number, since it uses as much as digits as its factorization.

21011012223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7003670744.

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 21011012223 its reverse (32221011012), we get a palindrome (53232023235).

The spelling of 21011012223 in words is "twenty-one billion, eleven million, twelve thousand, two hundred twenty-three".