21542809163 has 2 divisors, whose sum is σ = 21542809164. Its totient is φ = 21542809162.

The previous prime is 21542809157. The next prime is 21542809193. The reversal of 21542809163 is 36190824512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21542809163 - 2²⁸ = 21274373707 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21542809163.

It is not a weakly prime, because it can be changed into another prime (21542809153) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10771404581 + 10771404582.

It is an arithmetic number, because the mean of its divisors is an integer number (10771404582).

Almost surely, 2^21542809163 is an apocalyptic number.

21542809163 is a deficient number, since it is larger than the sum of its proper divisors (1).

21542809163 is an equidigital number, since it uses as much as digits as its factorization.

21542809163 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 103680, while the sum is 41.

The spelling of 21542809163 in words is "twenty-one billion, five hundred forty-two million, eight hundred nine thousand, one hundred sixty-three".