217384042 has 4 divisors (see below), whose sum is σ = 326076066. Its totient is φ = 108692020.

The previous prime is 217384039. The next prime is 217384051. The reversal of 217384042 is 240483712.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 189915961 + 27468081 = 13781^2 + 5241^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 217383995 and 217384013.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 54346009 + ... + 54346012.

Almost surely, 2^217384042 is an apocalyptic number.

217384042 is a deficient number, since it is larger than the sum of its proper divisors (108692024).

217384042 is a wasteful number, since it uses less digits than its factorization.

217384042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108692023.

The product of its (nonzero) digits is 10752, while the sum is 31.

The square root of 217384042 is about 14743.9493352358. The cubic root of 217384042 is about 601.2787929152.

The spelling of 217384042 in words is "two hundred seventeen million, three hundred eighty-four thousand, forty-two".