217812147 has 16 divisors (see below), whose sum is σ = 338967552. Its totient is φ = 121815360.

The previous prime is 217812137. The next prime is 217812163. The reversal of 217812147 is 741218712.

It is not a de Polignac number, because 217812147 - 2⁶ = 217812083 is a prime.

It is not an unprimeable number, because it can be changed into a prime (217812137) 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 15 ways as a sum of consecutive naturals, for example, 109354 + ... + 111327.

It is an arithmetic number, because the mean of its divisors is an integer number (21185472).

Almost surely, 2^217812147 is an apocalyptic number.

217812147 is a deficient number, since it is larger than the sum of its proper divisors (121155405).

217812147 is a wasteful number, since it uses less digits than its factorization.

217812147 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 220738.

The product of its digits is 6272, while the sum is 33.

The square root of 217812147 is about 14758.4601839081. The cubic root of 217812147 is about 601.6732433126.

The spelling of 217812147 in words is "two hundred seventeen million, eight hundred twelve thousand, one hundred forty-seven".