216541604261551 has 2 divisors, whose sum is σ = 216541604261552. Its totient is φ = 216541604261550.

The previous prime is 216541604261537. The next prime is 216541604261579. The reversal of 216541604261551 is 155162406145612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 216541604261551 - 2¹¹ = 216541604259503 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 216541604261495 and 216541604261504.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216541604261251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108270802130775 + 108270802130776.

It is an arithmetic number, because the mean of its divisors is an integer number (108270802130776).

Almost surely, 2^{216541604261551} is an apocalyptic number.

216541604261551 is a deficient number, since it is larger than the sum of its proper divisors (1).

216541604261551 is an equidigital number, since it uses as much as digits as its factorization.

216541604261551 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728000, while the sum is 49.

The spelling of 216541604261551 in words is "two hundred sixteen trillion, five hundred forty-one billion, six hundred four million, two hundred sixty-one thousand, five hundred fifty-one".