217434979 has 4 divisors (see below), whose sum is σ = 219094920. Its totient is φ = 215775040.

The previous prime is 217434941. The next prime is 217434983. The reversal of 217434979 is 979434712.

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

It is a cyclic number.

It is not a de Polignac number, because 217434979 - 2⁹ = 217434467 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (217438979) 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 3 ways as a sum of consecutive naturals, for example, 829774 + ... + 830035.

It is an arithmetic number, because the mean of its divisors is an integer number (54773730).

Almost surely, 2^217434979 is an apocalyptic number.

217434979 is a deficient number, since it is larger than the sum of its proper divisors (1659941).

217434979 is a wasteful number, since it uses less digits than its factorization.

217434979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1659940.

The product of its digits is 381024, while the sum is 46.

The square root of 217434979 is about 14745.6766206234. The cubic root of 217434979 is about 601.3257527345.

The spelling of 217434979 in words is "two hundred seventeen million, four hundred thirty-four thousand, nine hundred seventy-nine".