217471657969 has 2 divisors, whose sum is σ = 217471657970. Its totient is φ = 217471657968.

The previous prime is 217471657951. The next prime is 217471657979. The reversal of 217471657969 is 969756174712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 173398953744 + 44072704225 = 416412^2 + 209935^2 .

It is a cyclic number.

It is not a de Polignac number, because 217471657969 - 2¹⁵ = 217471625201 is a prime.

It is a super-2 number, since 2×217471657969² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 217471657969.

It is not a weakly prime, because it can be changed into another prime (217471657979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108735828984 + 108735828985.

It is an arithmetic number, because the mean of its divisors is an integer number (108735828985).

Almost surely, 2^217471657969 is an apocalyptic number.

It is an amenable number.

217471657969 is a deficient number, since it is larger than the sum of its proper divisors (1).

217471657969 is an equidigital number, since it uses as much as digits as its factorization.

217471657969 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40007520, while the sum is 64.

The spelling of 217471657969 in words is "two hundred seventeen billion, four hundred seventy-one million, six hundred fifty-seven thousand, nine hundred sixty-nine".