21202004123 has 2 divisors, whose sum is σ = 21202004124. Its totient is φ = 21202004122.

The previous prime is 21202004119. The next prime is 21202004191. The reversal of 21202004123 is 32140020212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21202004123 - 2² = 21202004119 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (21202004323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601002061 + 10601002062.

It is an arithmetic number, because the mean of its divisors is an integer number (10601002062).

Almost surely, 2^21202004123 is an apocalyptic number.

21202004123 is a deficient number, since it is larger than the sum of its proper divisors (1).

21202004123 is an equidigital number, since it uses as much as digits as its factorization.

21202004123 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 21202004123 its reverse (32140020212), we get a palindrome (53342024335).

The spelling of 21202004123 in words is "twenty-one billion, two hundred two million, four thousand, one hundred twenty-three".