217952661204 has 18 divisors (see below), whose sum is σ = 550935893690. Its totient is φ = 72650887056.

The previous prime is 217952661193. The next prime is 217952661221. The reversal of 217952661204 is 402166259712.

217952661204 is a `hidden beast` number, since 2 + 1 + 7 + 9 + 5 + 26 + 612 + 0 + 4 = 666.

It can be written as a sum of positive squares in only one way, i.e., 148920353604 + 69032307600 = 385902^2 + 262740^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a self number, because there is not a number n which added to its sum of digits gives 217952661204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3027120259 + ... + 3027120330.

Almost surely, 2^217952661204 is an apocalyptic number.

It is an amenable number.

217952661204 is an abundant number, since it is smaller than the sum of its proper divisors (332983232486).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

217952661204 is a wasteful number, since it uses less digits than its factorization.

217952661204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6054240599 (or 6054240594 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 45.

The spelling of 217952661204 in words is "two hundred seventeen billion, nine hundred fifty-two million, six hundred sixty-one thousand, two hundred four".