21312001003 has 2 divisors, whose sum is σ = 21312001004. Its totient is φ = 21312001002.

The previous prime is 21312001001. The next prime is 21312001019. The reversal of 21312001003 is 30010021312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21312001003 - 2¹ = 21312001001 is a prime.

Together with 21312001001, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21312001001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10656000501 + 10656000502.

It is an arithmetic number, because the mean of its divisors is an integer number (10656000502).

Almost surely, 2^21312001003 is an apocalyptic number.

21312001003 is a deficient number, since it is larger than the sum of its proper divisors (1).

21312001003 is an equidigital number, since it uses as much as digits as its factorization.

21312001003 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36, while the sum is 13.

Adding to 21312001003 its reverse (30010021312), we get a palindrome (51322022315).

The spelling of 21312001003 in words is "twenty-one billion, three hundred twelve million, one thousand, three".