217256242 has 8 divisors (see below), whose sum is σ = 372439296. Its totient is φ = 93109812.

The previous prime is 217256239. The next prime is 217256251. The reversal of 217256242 is 242652712.

It is a sphenic number, since it is the product of 3 distinct primes.

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 in 3 ways as a sum of consecutive naturals, for example, 7759138 + ... + 7759165.

It is an arithmetic number, because the mean of its divisors is an integer number (46554912).

Almost surely, 2^217256242 is an apocalyptic number.

217256242 is a deficient number, since it is larger than the sum of its proper divisors (155183054).

217256242 is a wasteful number, since it uses less digits than its factorization.

217256242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15518312.

The product of its digits is 13440, while the sum is 31.

The square root of 217256242 is about 14739.6147168099. The cubic root of 217256242 is about 601.1609392882.

The spelling of 217256242 in words is "two hundred seventeen million, two hundred fifty-six thousand, two hundred forty-two".