217139457204 has 18 divisors (see below), whose sum is σ = 548880294690. Its totient is φ = 72379819056.

The previous prime is 217139457203. The next prime is 217139457211. The reversal of 217139457204 is 402754931712.

217139457204 is a `hidden beast` number, since 2 + 1 + 7 + 1 + 394 + 57 + 204 = 666.

It can be written as a sum of positive squares in only one way, i.e., 146728834704 + 70410622500 = 383052^2 + 265350^2 .

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 217139457204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217139457203) 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 5 ways as a sum of consecutive naturals, for example, 3015825759 + ... + 3015825830.

It is an arithmetic number, because the mean of its divisors is an integer number (30493349705).

Almost surely, 2^217139457204 is an apocalyptic number.

It is an amenable number.

217139457204 is an abundant number, since it is smaller than the sum of its proper divisors (331740837486).

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

217139457204 is a wasteful number, since it uses less digits than its factorization.

217139457204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6031651599 (or 6031651594 counting only the distinct ones).

The product of its (nonzero) digits is 423360, while the sum is 45.

The spelling of 217139457204 in words is "two hundred seventeen billion, one hundred thirty-nine million, four hundred fifty-seven thousand, two hundred four".