217878134 has 4 divisors (see below), whose sum is σ = 326817204. Its totient is φ = 108939066.

The previous prime is 217878113. The next prime is 217878161. The reversal of 217878134 is 431878712.

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

It is a junction number, because it is equal to n+sod(n) for n = 217878091 and 217878100.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 54469532 + ... + 54469535.

It is an arithmetic number, because the mean of its divisors is an integer number (81704301).

Almost surely, 2^217878134 is an apocalyptic number.

217878134 is a deficient number, since it is larger than the sum of its proper divisors (108939070).

217878134 is a wasteful number, since it uses less digits than its factorization.

217878134 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108939069.

The product of its digits is 75264, while the sum is 41.

The square root of 217878134 is about 14760.6955798160. The cubic root of 217878134 is about 601.7339968934.

The spelling of 217878134 in words is "two hundred seventeen million, eight hundred seventy-eight thousand, one hundred thirty-four".