217106939176991 has 4 divisors (see below), whose sum is σ = 217110771051000. Its totient is φ = 217103107302984.

The previous prime is 217106939176969. The next prime is 217106939177017. The reversal of 217106939176991 is 199671939601712.

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

It is a cyclic number.

It is not a de Polignac number, because 217106939176991 - 2¹⁸ = 217106938914847 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217106939376991) 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, 1915852016 + ... + 1915965333.

It is an arithmetic number, because the mean of its divisors is an integer number (54277692762750).

Almost surely, 2^{217106939176991} is an apocalyptic number.

217106939176991 is a deficient number, since it is larger than the sum of its proper divisors (3831874009).

217106939176991 is an equidigital number, since it uses as much as digits as its factorization.

217106939176991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3831874008.

The product of its (nonzero) digits is 69441624, while the sum is 71.

The spelling of 217106939176991 in words is "two hundred seventeen trillion, one hundred six billion, nine hundred thirty-nine million, one hundred seventy-six thousand, nine hundred ninety-one".