217485215999 has 24 divisors (see below), whose sum is σ = 228061753920. Its totient is φ = 207368424000.

The previous prime is 217485215971. The next prime is 217485216019. The reversal of 217485215999 is 999512584712.

It is a de Polignac number, because none of the positive numbers 2^k-217485215999 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 (217485215939) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18953834 + ... + 18965304.

It is an arithmetic number, because the mean of its divisors is an integer number (9502573080).

Almost surely, 2^217485215999 is an apocalyptic number.

217485215999 is a deficient number, since it is larger than the sum of its proper divisors (10576537921).

217485215999 is a wasteful number, since it uses less digits than its factorization.

217485215999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11823 (or 11792 counting only the distinct ones).

The product of its digits is 16329600, while the sum is 62.

The spelling of 217485215999 in words is "two hundred seventeen billion, four hundred eighty-five million, two hundred fifteen thousand, nine hundred ninety-nine".