216465566857 has 2 divisors, whose sum is σ = 216465566858. Its totient is φ = 216465566856.

The previous prime is 216465566843. The next prime is 216465566921. The reversal of 216465566857 is 758665564612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 129712344336 + 86753222521 = 360156^2 + 294539^2 .

It is a cyclic number.

It is not a de Polignac number, because 216465566857 - 2³¹ = 214318083209 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 216465566795 and 216465566804.

It is not a weakly prime, because it can be changed into another prime (216465566657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108232783428 + 108232783429.

It is an arithmetic number, because the mean of its divisors is an integer number (108232783429).

Almost surely, 2^216465566857 is an apocalyptic number.

It is an amenable number.

216465566857 is a deficient number, since it is larger than the sum of its proper divisors (1).

216465566857 is an equidigital number, since it uses as much as digits as its factorization.

216465566857 is an evil number, because the sum of its binary digits is even.

The product of its digits is 72576000, while the sum is 61.

The spelling of 216465566857 in words is "two hundred sixteen billion, four hundred sixty-five million, five hundred sixty-six thousand, eight hundred fifty-seven".