21312321307 has 2 divisors, whose sum is σ = 21312321308. Its totient is φ = 21312321306.

The previous prime is 21312321287. The next prime is 21312321319. The reversal of 21312321307 is 70312321312.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21312321307 - 2¹⁵ = 21312288539 is a prime.

It is not a weakly prime, because it can be changed into another prime (21312321007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10656160653 + 10656160654.

It is an arithmetic number, because the mean of its divisors is an integer number (10656160654).

Almost surely, 2^21312321307 is an apocalyptic number.

21312321307 is a deficient number, since it is larger than the sum of its proper divisors (1).

21312321307 is an equidigital number, since it uses as much as digits as its factorization.

21312321307 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1512, while the sum is 25.

Adding to 21312321307 its reverse (70312321312), we get a palindrome (91624642619).

The spelling of 21312321307 in words is "twenty-one billion, three hundred twelve million, three hundred twenty-one thousand, three hundred seven".