21312123303 has 16 divisors (see below), whose sum is σ = 28821056000. Its totient is φ = 14006947680.

The previous prime is 21312123289. The next prime is 21312123337. The reversal of 21312123303 is 30332121312.

It is not a de Polignac number, because 21312123303 - 2⁸ = 21312123047 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21312123303.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21312123383) 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 15 ways as a sum of consecutive naturals, for example, 98683 + ... + 228828.

It is an arithmetic number, because the mean of its divisors is an integer number (1801316000).

Almost surely, 2^21312123303 is an apocalyptic number.

21312123303 is a deficient number, since it is larger than the sum of its proper divisors (7508932697).

21312123303 is a wasteful number, since it uses less digits than its factorization.

21312123303 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 327822.

The product of its (nonzero) digits is 648, while the sum is 21.

Adding to 21312123303 its reverse (30332121312), we get a palindrome (51644244615).

The spelling of 21312123303 in words is "twenty-one billion, three hundred twelve million, one hundred twenty-three thousand, three hundred three".