21563303623 has 10 divisors (see below), whose sum is σ = 22761393304. Its totient is φ = 20428269444.

The previous prime is 21563303617. The next prime is 21563303639. The reversal of 21563303623 is 32630336512.

It is not a de Polignac number, because 21563303623 - 2¹⁷ = 21563172551 is a prime.

It is a super-2 number, since 2×21563303623² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21563301623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 47590 + ... + 213052.

Almost surely, 2^21563303623 is an apocalyptic number.

21563303623 is a deficient number, since it is larger than the sum of its proper divisors (1198089681).

21563303623 is an frugal number, since it uses more digits than its factorization.

21563303623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165539 (or 165482 counting only the distinct ones).

The product of its (nonzero) digits is 58320, while the sum is 34.

The spelling of 21563303623 in words is "twenty-one billion, five hundred sixty-three million, three hundred three thousand, six hundred twenty-three".