21540316867 has 2 divisors, whose sum is σ = 21540316868. Its totient is φ = 21540316866.

The previous prime is 21540316841. The next prime is 21540316877. The reversal of 21540316867 is 76861304512.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21540316867 is a prime.

It is not a weakly prime, because it can be changed into another prime (21540316817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10770158433 + 10770158434.

It is an arithmetic number, because the mean of its divisors is an integer number (10770158434).

Almost surely, 2^21540316867 is an apocalyptic number.

21540316867 is a deficient number, since it is larger than the sum of its proper divisors (1).

21540316867 is an equidigital number, since it uses as much as digits as its factorization.

21540316867 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 241920, while the sum is 43.

The spelling of 21540316867 in words is "twenty-one billion, five hundred forty million, three hundred sixteen thousand, eight hundred sixty-seven".