217985402397 has 8 divisors (see below), whose sum is σ = 332168232256. Its totient is φ = 124563087072.

The previous prime is 217985402381. The next prime is 217985402399. The reversal of 217985402397 is 793204589712.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 217985402397 - 2⁴ = 217985402381 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217985402399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5190128608 + ... + 5190128649.

It is an arithmetic number, because the mean of its divisors is an integer number (41521029032).

Almost surely, 2^217985402397 is an apocalyptic number.

It is an amenable number.

217985402397 is a deficient number, since it is larger than the sum of its proper divisors (114182829859).

217985402397 is a wasteful number, since it uses less digits than its factorization.

217985402397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10380257267.

The product of its (nonzero) digits is 7620480, while the sum is 57.

The spelling of 217985402397 in words is "two hundred seventeen billion, nine hundred eighty-five million, four hundred two thousand, three hundred ninety-seven".