21000122120123 has 2 divisors, whose sum is σ = 21000122120124. Its totient is φ = 21000122120122.

The previous prime is 21000122120099. The next prime is 21000122120137. The reversal of 21000122120123 is 32102122100012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21000122120123 - 2⁴² = 16602075609019 is a prime.

It is not a weakly prime, because it can be changed into another prime (21000122125123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500061060061 + 10500061060062.

It is an arithmetic number, because the mean of its divisors is an integer number (10500061060062).

Almost surely, 2^{21000122120123} is an apocalyptic number.

21000122120123 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000122120123 is an equidigital number, since it uses as much as digits as its factorization.

21000122120123 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 21000122120123 its reverse (32102122100012), we get a palindrome (53102244220135).

The spelling of 21000122120123 in words is "twenty-one trillion, one hundred twenty-two million, one hundred twenty thousand, one hundred twenty-three".