217993534749 has 12 divisors (see below), whose sum is σ = 319579245856. Its totient is φ = 143159932872.

The previous prime is 217993534723. The next prime is 217993534769. The reversal of 217993534749 is 947435399712.

217993534749 is a `hidden beast` number, since 2 + 1 + 7 + 9 + 93 + 534 + 7 + 4 + 9 = 666.

It is not a de Polignac number, because 217993534749 - 2⁷ = 217993534621 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 (217993534769) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 180756889 + ... + 180758094.

Almost surely, 2^217993534749 is an apocalyptic number.

It is an amenable number.

217993534749 is a deficient number, since it is larger than the sum of its proper divisors (101585711107).

217993534749 is a wasteful number, since it uses less digits than its factorization.

217993534749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 361515056 (or 361515053 counting only the distinct ones).

The product of its digits is 51438240, while the sum is 63.

The spelling of 217993534749 in words is "two hundred seventeen billion, nine hundred ninety-three million, five hundred thirty-four thousand, seven hundred forty-nine".