21030203123 has 2 divisors, whose sum is σ = 21030203124. Its totient is φ = 21030203122.

The previous prime is 21030203101. The next prime is 21030203149. The reversal of 21030203123 is 32130203012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21030203123 - 2⁶ = 21030203059 is a prime.

It is not a weakly prime, because it can be changed into another prime (21030203023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10515101561 + 10515101562.

It is an arithmetic number, because the mean of its divisors is an integer number (10515101562).

Almost surely, 2^21030203123 is an apocalyptic number.

21030203123 is a deficient number, since it is larger than the sum of its proper divisors (1).

21030203123 is an equidigital number, since it uses as much as digits as its factorization.

21030203123 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 17.

Adding to 21030203123 its reverse (32130203012), we get a palindrome (53160406135).

The spelling of 21030203123 in words is "twenty-one billion, thirty million, two hundred three thousand, one hundred twenty-three".