21045636441 has 6 divisors (see below), whose sum is σ = 30399252650. Its totient is φ = 14030424288.

The previous prime is 21045636439. The next prime is 21045636457. The reversal of 21045636441 is 14463654012.

21045636441 is a `hidden beast` number, since 2 + 1 + 0 + 4 + 5 + 6 + 3 + 644 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 20139867225 + 905769216 = 141915^2 + 30096^2 .

It is not a de Polignac number, because 21045636441 - 2¹ = 21045636439 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21045636396 and 21045636405.

It is not an unprimeable number, because it can be changed into a prime (21045636481) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1169202016 + ... + 1169202033.

Almost surely, 2^21045636441 is an apocalyptic number.

It is an amenable number.

21045636441 is a deficient number, since it is larger than the sum of its proper divisors (9353616209).

21045636441 is a wasteful number, since it uses less digits than its factorization.

21045636441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2338404055 (or 2338404052 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 36.

The spelling of 21045636441 in words is "twenty-one billion, forty-five million, six hundred thirty-six thousand, four hundred forty-one".