217579234681 has 2 divisors, whose sum is σ = 217579234682. Its totient is φ = 217579234680.

The previous prime is 217579234669. The next prime is 217579234703. The reversal of 217579234681 is 186432975712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 182153972025 + 35425262656 = 426795^2 + 188216^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-217579234681 is a prime.

It is a super-2 number, since 2×217579234681² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (217579234651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108789617340 + 108789617341.

It is an arithmetic number, because the mean of its divisors is an integer number (108789617341).

Almost surely, 2^217579234681 is an apocalyptic number.

It is an amenable number.

217579234681 is a deficient number, since it is larger than the sum of its proper divisors (1).

217579234681 is an equidigital number, since it uses as much as digits as its factorization.

217579234681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5080320, while the sum is 55.

The spelling of 217579234681 in words is "two hundred seventeen billion, five hundred seventy-nine million, two hundred thirty-four thousand, six hundred eighty-one".