21503316163 has 12 divisors (see below), whose sum is σ = 25017760560. Its totient is φ = 18428688432.

The previous prime is 21503316143. The next prime is 21503316173. The reversal of 21503316163 is 36161330512.

It is not a de Polignac number, because 21503316163 - 2²¹ = 21501219011 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21503316143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 347170 + ... + 404392.

It is an arithmetic number, because the mean of its divisors is an integer number (2084813380).

Almost surely, 2^21503316163 is an apocalyptic number.

21503316163 is a deficient number, since it is larger than the sum of its proper divisors (3514444397).

21503316163 is an equidigital number, since it uses as much as digits as its factorization.

21503316163 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64906 (or 64899 counting only the distinct ones).

The product of its (nonzero) digits is 9720, while the sum is 31.

Adding to 21503316163 its reverse (36161330512), we get a palindrome (57664646675).

The spelling of 21503316163 in words is "twenty-one billion, five hundred three million, three hundred sixteen thousand, one hundred sixty-three".