21012220223 has 2 divisors, whose sum is σ = 21012220224. Its totient is φ = 21012220222.

The previous prime is 21012220211. The next prime is 21012220241. The reversal of 21012220223 is 32202221012.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21012220223 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (23012220223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506110111 + 10506110112.

It is an arithmetic number, because the mean of its divisors is an integer number (10506110112).

Almost surely, 2^21012220223 is an apocalyptic number.

21012220223 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012220223 is an equidigital number, since it uses as much as digits as its factorization.

21012220223 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 192, while the sum is 17.

Adding to 21012220223 its reverse (32202221012), we get a palindrome (53214441235).

The spelling of 21012220223 in words is "twenty-one billion, twelve million, two hundred twenty thousand, two hundred twenty-three".