21271004105 has 16 divisors (see below), whose sum is σ = 27555926160. Its totient is φ = 15669393408.

The previous prime is 21271004099. The next prime is 21271004107. The reversal of 21271004105 is 50140017212.

It can be written as a sum of positive squares in 8 ways, for example, as 3447686089 + 17823318016 = 58717^2 + 133504^2 .

It is a cyclic number.

It is not a de Polignac number, because 21271004105 - 2⁸ = 21271003849 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21271004107) 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, 373472 + ... + 426641.

It is an arithmetic number, because the mean of its divisors is an integer number (1722245385).

Almost surely, 2^21271004105 is an apocalyptic number.

It is an amenable number.

21271004105 is a deficient number, since it is larger than the sum of its proper divisors (6284922055).

21271004105 is a wasteful number, since it uses less digits than its factorization.

21271004105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 800540.

The product of its (nonzero) digits is 560, while the sum is 23.

The spelling of 21271004105 in words is "twenty-one billion, two hundred seventy-one million, four thousand, one hundred five".