21123203031203 has 24 divisors (see below), whose sum is σ = 26463326829408. Its totient is φ = 16712047771776.

The previous prime is 21123203031197. The next prime is 21123203031223. The reversal of 21123203031203 is 30213030232112.

It is not a de Polignac number, because 21123203031203 - 2⁸ = 21123203030947 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21123203031223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12413975 + ... + 14012607.

It is an arithmetic number, because the mean of its divisors is an integer number (1102638617892).

Almost surely, 2^{21123203031203} is an apocalyptic number.

21123203031203 is a deficient number, since it is larger than the sum of its proper divisors (5340123798205).

21123203031203 is a wasteful number, since it uses less digits than its factorization.

21123203031203 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1619403 (or 1619396 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 23.

Adding to 21123203031203 its reverse (30213030232112), we get a palindrome (51336233263315).

The spelling of 21123203031203 in words is "twenty-one trillion, one hundred twenty-three billion, two hundred three million, thirty-one thousand, two hundred three".