21541636163 has 2 divisors, whose sum is σ = 21541636164. Its totient is φ = 21541636162.

The previous prime is 21541636141. The next prime is 21541636177. The reversal of 21541636163 is 36163614512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21541636163 - 2²⁶ = 21474527299 is a prime.

It is not a weakly prime, because it can be changed into another prime (21541633163) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10770818081 + 10770818082.

It is an arithmetic number, because the mean of its divisors is an integer number (10770818082).

Almost surely, 2^21541636163 is an apocalyptic number.

21541636163 is a deficient number, since it is larger than the sum of its proper divisors (1).

21541636163 is an equidigital number, since it uses as much as digits as its factorization.

21541636163 is an evil number, because the sum of its binary digits is even.

The product of its digits is 77760, while the sum is 38.

The spelling of 21541636163 in words is "twenty-one billion, five hundred forty-one million, six hundred thirty-six thousand, one hundred sixty-three".