21271003563 has 16 divisors (see below), whose sum is σ = 28593202176. Its totient is φ = 14064853920.

The previous prime is 21271003561. The next prime is 21271003651. The reversal of 21271003563 is 36530017212.

It is not a de Polignac number, because 21271003563 - 2¹ = 21271003561 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21271003563.

It is not an unprimeable number, because it can be changed into a prime (21271003561) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 771270 + ... + 798372.

It is an arithmetic number, because the mean of its divisors is an integer number (1787075136).

Almost surely, 2^21271003563 is an apocalyptic number.

21271003563 is a deficient number, since it is larger than the sum of its proper divisors (7322198613).

21271003563 is a wasteful number, since it uses less digits than its factorization.

21271003563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29234.

The product of its (nonzero) digits is 7560, while the sum is 30.

The spelling of 21271003563 in words is "twenty-one billion, two hundred seventy-one million, three thousand, five hundred sixty-three".