21321442403123 has 2 divisors, whose sum is σ = 21321442403124. Its totient is φ = 21321442403122.

The previous prime is 21321442403089. The next prime is 21321442403153. The reversal of 21321442403123 is 32130424412312.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21321442403123 - 2⁶ = 21321442403059 is a prime.

It is a super-2 number, since 2×21321442403123² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21321442403123.

It is not a weakly prime, because it can be changed into another prime (21321442403153) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10660721201561 + 10660721201562.

It is an arithmetic number, because the mean of its divisors is an integer number (10660721201562).

Almost surely, 2^{21321442403123} is an apocalyptic number.

21321442403123 is a deficient number, since it is larger than the sum of its proper divisors (1).

21321442403123 is an equidigital number, since it uses as much as digits as its factorization.

21321442403123 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 27648, while the sum is 32.

Adding to 21321442403123 its reverse (32130424412312), we get a palindrome (53451866815435).

The spelling of 21321442403123 in words is "twenty-one trillion, three hundred twenty-one billion, four hundred forty-two million, four hundred three thousand, one hundred twenty-three".