217028939 has 12 divisors (see below), whose sum is σ = 227866464. Its totient is φ = 206609184.

The previous prime is 217028921. The next prime is 217028941. The reversal of 217028939 is 939820712.

It is a happy number.

It is not a de Polignac number, because 217028939 - 2⁸ = 217028683 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 217028896 and 217028905.

It is not an unprimeable number, because it can be changed into a prime (217028639) 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 11 ways as a sum of consecutive naturals, for example, 62657 + ... + 66029.

It is an arithmetic number, because the mean of its divisors is an integer number (18988872).

Almost surely, 2^217028939 is an apocalyptic number.

217028939 is a deficient number, since it is larger than the sum of its proper divisors (10837525).

217028939 is an equidigital number, since it uses as much as digits as its factorization.

217028939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3494 (or 3457 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 41.

The square root of 217028939 is about 14731.9020835736. The cubic root of 217028939 is about 600.9512124907.

The spelling of 217028939 in words is "two hundred seventeen million, twenty-eight thousand, nine hundred thirty-nine".