21203000123 has 2 divisors, whose sum is σ = 21203000124. Its totient is φ = 21203000122.

The previous prime is 21203000101. The next prime is 21203000197. The reversal of 21203000123 is 32100030212.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21203000123 - 2²⁴ = 21186222907 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21203000098 and 21203000107.

It is not a weakly prime, because it can be changed into another prime (21203000023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601500061 + 10601500062.

It is an arithmetic number, because the mean of its divisors is an integer number (10601500062).

Almost surely, 2^21203000123 is an apocalyptic number.

21203000123 is a deficient number, since it is larger than the sum of its proper divisors (1).

21203000123 is an equidigital number, since it uses as much as digits as its factorization.

21203000123 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 14.

Adding to 21203000123 its reverse (32100030212), we get a palindrome (53303030335).

The spelling of 21203000123 in words is "twenty-one billion, two hundred three million, one hundred twenty-three", and thus it is an aban number.