21540324377287 has 2 divisors, whose sum is σ = 21540324377288. Its totient is φ = 21540324377286.

The previous prime is 21540324377239. The next prime is 21540324377303. The reversal of 21540324377287 is 78277342304512.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21540324377287 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21540324377687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10770162188643 + 10770162188644.

It is an arithmetic number, because the mean of its divisors is an integer number (10770162188644).

Almost surely, 2^{21540324377287} is an apocalyptic number.

21540324377287 is a deficient number, since it is larger than the sum of its proper divisors (1).

21540324377287 is an equidigital number, since it uses as much as digits as its factorization.

21540324377287 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15805440, while the sum is 55.

The spelling of 21540324377287 in words is "twenty-one trillion, five hundred forty billion, three hundred twenty-four million, three hundred seventy-seven thousand, two hundred eighty-seven".