21503100425021 has 2 divisors, whose sum is σ = 21503100425022. Its totient is φ = 21503100425020.

The previous prime is 21503100424937. The next prime is 21503100425071. The reversal of 21503100425021 is 12052400130512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20443464888025 + 1059635536996 = 4521445^2 + 1029386^2 .

It is a cyclic number.

It is not a de Polignac number, because 21503100425021 - 2³⁸ = 21228222518077 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21503100425071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10751550212510 + 10751550212511.

It is an arithmetic number, because the mean of its divisors is an integer number (10751550212511).

Almost surely, 2^{21503100425021} is an apocalyptic number.

It is an amenable number.

21503100425021 is a deficient number, since it is larger than the sum of its proper divisors (1).

21503100425021 is an equidigital number, since it uses as much as digits as its factorization.

21503100425021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2400, while the sum is 26.

Adding to 21503100425021 its reverse (12052400130512), we get a palindrome (33555500555533).

The spelling of 21503100425021 in words is "twenty-one trillion, five hundred three billion, one hundred million, four hundred twenty-five thousand, twenty-one".