216661262217651 has 12 divisors (see below), whose sum is σ = 317626129023112. Its totient is φ = 142285008023136.

The previous prime is 216661262217629. The next prime is 216661262217683. The reversal of 216661262217651 is 156712262166612.

It is not a de Polignac number, because 216661262217651 - 2¹⁰ = 216661262216627 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216661262217551) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 179652787306 + ... + 179652788511.

Almost surely, 2^{216661262217651} is an apocalyptic number.

216661262217651 is a deficient number, since it is larger than the sum of its proper divisors (100964866805461).

216661262217651 is a wasteful number, since it uses less digits than its factorization.

216661262217651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 359305575890 (or 359305575887 counting only the distinct ones).

The product of its digits is 4354560, while the sum is 54.

The spelling of 216661262217651 in words is "two hundred sixteen trillion, six hundred sixty-one billion, two hundred sixty-two million, two hundred seventeen thousand, six hundred fifty-one".