21636531041 has 4 divisors (see below), whose sum is σ = 21636892692. Its totient is φ = 21636169392.

The previous prime is 21636531031. The next prime is 21636531047. The reversal of 21636531041 is 14013563612.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 18062284816 + 3574246225 = 134396^2 + 59785^2 .

It is a cyclic number.

It is not a de Polignac number, because 21636531041 - 2²⁶ = 21569422177 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21636530989 and 21636531007.

It is not an unprimeable number, because it can be changed into a prime (21636531047) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 67346 + ... + 218651.

It is an arithmetic number, because the mean of its divisors is an integer number (5409223173).

Almost surely, 2^21636531041 is an apocalyptic number.

It is an amenable number.

21636531041 is a deficient number, since it is larger than the sum of its proper divisors (361651).

21636531041 is an equidigital number, since it uses as much as digits as its factorization.

21636531041 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 361650.

The product of its (nonzero) digits is 12960, while the sum is 32.

The spelling of 21636531041 in words is "twenty-one billion, six hundred thirty-six million, five hundred thirty-one thousand, forty-one".