216256847549 has 2 divisors, whose sum is σ = 216256847550. Its totient is φ = 216256847548.

The previous prime is 216256847533. The next prime is 216256847617. The reversal of 216256847549 is 945748652612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 171193200025 + 45063647524 = 413755^2 + 212282^2 .

It is a cyclic number.

It is not a de Polignac number, because 216256847549 - 2⁴ = 216256847533 is a prime.

It is a super-2 number, since 2×216256847549² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216256847249) 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, 108128423774 + 108128423775.

It is an arithmetic number, because the mean of its divisors is an integer number (108128423775).

Almost surely, 2^216256847549 is an apocalyptic number.

It is an amenable number.

216256847549 is a deficient number, since it is larger than the sum of its proper divisors (1).

216256847549 is an equidigital number, since it uses as much as digits as its factorization.

216256847549 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 29030400, while the sum is 59.

The spelling of 216256847549 in words is "two hundred sixteen billion, two hundred fifty-six million, eight hundred forty-seven thousand, five hundred forty-nine".