21312120029 has 2 divisors, whose sum is σ = 21312120030. Its totient is φ = 21312120028.

The previous prime is 21312119993. The next prime is 21312120031. The reversal of 21312120029 is 92002121312.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20081724100 + 1230395929 = 141710^2 + 35077^2 .

It is a cyclic number.

It is not a de Polignac number, because 21312120029 - 2¹² = 21312115933 is a prime.

Together with 21312120031, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21312119986 and 21312120013.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21312120829) 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 as a sum of consecutive naturals, namely, 10656060014 + 10656060015.

It is an arithmetic number, because the mean of its divisors is an integer number (10656060015).

Almost surely, 2^21312120029 is an apocalyptic number.

It is an amenable number.

21312120029 is a deficient number, since it is larger than the sum of its proper divisors (1).

21312120029 is an equidigital number, since it uses as much as digits as its factorization.

21312120029 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 23.

The spelling of 21312120029 in words is "twenty-one billion, three hundred twelve million, one hundred twenty thousand, twenty-nine".