216226920561 has 12 divisors (see below), whose sum is σ = 298586841072. Its totient is φ = 139180544944.

The previous prime is 216226920521. The next prime is 216226920563. The reversal of 216226920561 is 165029622612.

It is not a de Polignac number, because 216226920561 - 2¹⁹ = 216226396273 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (216226920563) 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, 42848631 + ... + 42853676.

It is an arithmetic number, because the mean of its divisors is an integer number (24882236756).

Almost surely, 2^216226920561 is an apocalyptic number.

It is an amenable number.

216226920561 is a deficient number, since it is larger than the sum of its proper divisors (82359920511).

216226920561 is an equidigital number, since it uses as much as digits as its factorization.

216226920561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85702368 (or 85702339 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 42.

The spelling of 216226920561 in words is "two hundred sixteen billion, two hundred twenty-six million, nine hundred twenty thousand, five hundred sixty-one".