312403120021 has 2 divisors, whose sum is σ = 312403120022. Its totient is φ = 312403120020.

The previous prime is 312403120019. The next prime is 312403120039. The reversal of 312403120021 is 120021304213.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 232449336900 + 79953783121 = 482130^2 + 282761^2 .

It is an emirp because it is prime and its reverse (120021304213) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 312403120021 - 2¹ = 312403120019 is a prime.

Together with 312403120019, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (312403120921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 156201560010 + 156201560011.

It is an arithmetic number, because the mean of its divisors is an integer number (156201560011).

Almost surely, 2^312403120021 is an apocalyptic number.

It is an amenable number.

312403120021 is a deficient number, since it is larger than the sum of its proper divisors (1).

312403120021 is an equidigital number, since it uses as much as digits as its factorization.

312403120021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 312403120021 its reverse (120021304213), we get a palindrome (432424424234).

The spelling of 312403120021 in words is "three hundred twelve billion, four hundred three million, one hundred twenty thousand, twenty-one".