217950998101 has 4 divisors (see below), whose sum is σ = 218146120972. Its totient is φ = 217755875232.

The previous prime is 217950998071. The next prime is 217950998143. The reversal of 217950998101 is 101899059712.

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 65932887076 + 152018111025 = 256774^2 + 389895^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-217950998101 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 (217950098101) 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, 97559760 + ... + 97561993.

It is an arithmetic number, because the mean of its divisors is an integer number (54536530243).

Almost surely, 2^217950998101 is an apocalyptic number.

It is an amenable number.

217950998101 is a deficient number, since it is larger than the sum of its proper divisors (195122871).

217950998101 is a wasteful number, since it uses less digits than its factorization.

217950998101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195122870.

The product of its (nonzero) digits is 408240, while the sum is 52.

The spelling of 217950998101 in words is "two hundred seventeen billion, nine hundred fifty million, nine hundred ninety-eight thousand, one hundred one".