217661713 has 4 divisors (see below), whose sum is σ = 223544500. Its totient is φ = 211778928.

The previous prime is 217661711. The next prime is 217661723. The reversal of 217661713 is 317166712.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 157552704 + 60109009 = 12552^2 + 7753^2 .

It is a cyclic number.

It is not a de Polignac number, because 217661713 - 2¹ = 217661711 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (217661711) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2941338 + ... + 2941411.

It is an arithmetic number, because the mean of its divisors is an integer number (55886125).

Almost surely, 2^217661713 is an apocalyptic number.

It is an amenable number.

217661713 is a deficient number, since it is larger than the sum of its proper divisors (5882787).

217661713 is an equidigital number, since it uses as much as digits as its factorization.

217661713 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5882786.

The product of its digits is 10584, while the sum is 34.

The square root of 217661713 is about 14753.3627692130. The cubic root of 217661713 is about 601.5346943235.

The spelling of 217661713 in words is "two hundred seventeen million, six hundred sixty-one thousand, seven hundred thirteen".