2003121131621 has 2 divisors, whose sum is σ = 2003121131622. Its totient is φ = 2003121131620.

The previous prime is 2003121131593. The next prime is 2003121131653. The reversal of 2003121131621 is 1261311213002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1315815468100 + 687305663521 = 1147090^2 + 829039^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2003121131621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2003121131681) 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 as a sum of consecutive naturals, namely, 1001560565810 + 1001560565811.

It is an arithmetic number, because the mean of its divisors is an integer number (1001560565811).

Almost surely, 2^{2003121131621} is an apocalyptic number.

It is an amenable number.

2003121131621 is a deficient number, since it is larger than the sum of its proper divisors (1).

2003121131621 is an equidigital number, since it uses as much as digits as its factorization.

2003121131621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 23.

Adding to 2003121131621 its reverse (1261311213002), we get a palindrome (3264432344623).

The spelling of 2003121131621 in words is "two trillion, three billion, one hundred twenty-one million, one hundred thirty-one thousand, six hundred twenty-one".