21547557359 has 2 divisors, whose sum is σ = 21547557360. Its totient is φ = 21547557358.

The previous prime is 21547557347. The next prime is 21547557379. The reversal of 21547557359 is 95375574512.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21547557359 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21547557359.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21547557379) 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, 10773778679 + 10773778680.

It is an arithmetic number, because the mean of its divisors is an integer number (10773778680).

Almost surely, 2^21547557359 is an apocalyptic number.

21547557359 is a deficient number, since it is larger than the sum of its proper divisors (1).

21547557359 is an equidigital number, since it uses as much as digits as its factorization.

21547557359 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6615000, while the sum is 53.

The spelling of 21547557359 in words is "twenty-one billion, five hundred forty-seven million, five hundred fifty-seven thousand, three hundred fifty-nine".