21003203320381 has 2 divisors, whose sum is σ = 21003203320382. Its totient is φ = 21003203320380.

The previous prime is 21003203320349. The next prime is 21003203320399. The reversal of 21003203320381 is 18302330230012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17469683105625 + 3533520214756 = 4179675^2 + 1879766^2 .

It is a cyclic number.

It is not a de Polignac number, because 21003203320381 - 2⁵ = 21003203320349 is a prime.

It is a super-2 number, since 2×21003203320381² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21003203300381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10501601660190 + 10501601660191.

It is an arithmetic number, because the mean of its divisors is an integer number (10501601660191).

Almost surely, 2^{21003203320381} is an apocalyptic number.

It is an amenable number.

21003203320381 is a deficient number, since it is larger than the sum of its proper divisors (1).

21003203320381 is an equidigital number, since it uses as much as digits as its factorization.

21003203320381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5184, while the sum is 28.

Adding to 21003203320381 its reverse (18302330230012), we get a palindrome (39305533550393).

The spelling of 21003203320381 in words is "twenty-one trillion, three billion, two hundred three million, three hundred twenty thousand, three hundred eighty-one".