21123321122129 has 4 divisors (see below), whose sum is σ = 21201266956800. Its totient is φ = 21045375287460.

The previous prime is 21123321122021. The next prime is 21123321122131. The reversal of 21123321122129 is 92122112332112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21123321122129 - 2⁴⁴ = 3531135077713 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21123321122095 and 21123321122104.

It is not an unprimeable number, because it can be changed into a prime (21123320122129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38972916929 + ... + 38972917470.

It is an arithmetic number, because the mean of its divisors is an integer number (5300316739200).

Almost surely, 2^{21123321122129} is an apocalyptic number.

It is an amenable number.

21123321122129 is a deficient number, since it is larger than the sum of its proper divisors (77945834671).

21123321122129 is an equidigital number, since it uses as much as digits as its factorization.

21123321122129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77945834670.

The product of its digits is 5184, while the sum is 32.

The spelling of 21123321122129 in words is "twenty-one trillion, one hundred twenty-three billion, three hundred twenty-one million, one hundred twenty-two thousand, one hundred twenty-nine".