217661371215107 has 4 divisors (see below), whose sum is σ = 217847247707496. Its totient is φ = 217475494722720.

The previous prime is 217661371215031. The next prime is 217661371215121. The reversal of 217661371215107 is 701512173166712.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-217661371215107 is a prime.

It is a super-2 number, since 2×217661371215107² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (217661373215107) 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, 92938244438 + ... + 92938246779.

It is an arithmetic number, because the mean of its divisors is an integer number (54461811926874).

Almost surely, 2^{217661371215107} is an apocalyptic number.

217661371215107 is a deficient number, since it is larger than the sum of its proper divisors (185876492389).

217661371215107 is a wasteful number, since it uses less digits than its factorization.

217661371215107 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185876492388.

The product of its (nonzero) digits is 740880, while the sum is 50.

The spelling of 217661371215107 in words is "two hundred seventeen trillion, six hundred sixty-one billion, three hundred seventy-one million, two hundred fifteen thousand, one hundred seven".