21066461606503 has 2 divisors, whose sum is σ = 21066461606504. Its totient is φ = 21066461606502.

The previous prime is 21066461606479. The next prime is 21066461606557. The reversal of 21066461606503 is 30560616466012.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21066461606503 - 2⁵ = 21066461606471 is a prime.

It is a super-2 number, since 2×21066461606503² (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 (21066461606573) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10533230803251 + 10533230803252.

It is an arithmetic number, because the mean of its divisors is an integer number (10533230803252).

Almost surely, 2^{21066461606503} is an apocalyptic number.

21066461606503 is a deficient number, since it is larger than the sum of its proper divisors (1).

21066461606503 is an equidigital number, since it uses as much as digits as its factorization.

21066461606503 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 933120, while the sum is 46.

The spelling of 21066461606503 in words is "twenty-one trillion, sixty-six billion, four hundred sixty-one million, six hundred six thousand, five hundred three".