217094557388641 has 27 divisors (see below), whose sum is σ = 226391287884339. Its totient is φ = 208175561815200.

The previous prime is 217094557388591. The next prime is 217094557388647. The reversal of 217094557388641 is 146883755490712.

It is a happy number.

The square root of 217094557388641 is 14734129.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 10460832331041 + 206633725057600 = 3234321^2 + 14374760^2 .

It is a de Polignac number, because none of the positive numbers 2^k-217094557388641 is a prime.

It is a Smith number, since the sum of its digits (70) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (217094557388647) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 35641855006 + ... + 35641861096.

It is a 1-persistent number, because it is pandigital, but 2⋅217094557388641 = 434189114777282 is not.

Almost surely, 2^{217094557388641} is an apocalyptic number.

217094557388641 is the 14734129-th square number.

217094557388641 is the 7367065-th centered octagonal number.

It is an amenable number.

217094557388641 is a deficient number, since it is larger than the sum of its proper divisors (9296730495698).

217094557388641 is an frugal number, since it uses more digits than its factorization.

217094557388641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12382 (or 6191 counting only the distinct ones).

The product of its (nonzero) digits is 406425600, while the sum is 70.

The spelling of 217094557388641 in words is "two hundred seventeen trillion, ninety-four billion, five hundred fifty-seven million, three hundred eighty-eight thousand, six hundred forty-one".