21210021212123 has 2 divisors, whose sum is σ = 21210021212124. Its totient is φ = 21210021212122.

The previous prime is 21210021212089. The next prime is 21210021212147. The reversal of 21210021212123 is 32121212001212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21210021212123 - 2²⁴ = 21210004434907 is a prime.

It is a super-2 number, since 2×21210021212123² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21210021212095 and 21210021212104.

It is not a weakly prime, because it can be changed into another prime (21210021211123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605010606061 + 10605010606062.

It is an arithmetic number, because the mean of its divisors is an integer number (10605010606062).

Almost surely, 2^{21210021212123} is an apocalyptic number.

21210021212123 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210021212123 is an equidigital number, since it uses as much as digits as its factorization.

21210021212123 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 20.

Adding to 21210021212123 its reverse (32121212001212), we get a palindrome (53331233213335).

The spelling of 21210021212123 in words is "twenty-one trillion, two hundred ten billion, twenty-one million, two hundred twelve thousand, one hundred twenty-three".