217028690 has 16 divisors (see below), whose sum is σ = 407636928. Its totient is φ = 83036976.

The previous prime is 217028689. The next prime is 217028711. The reversal of 217028690 is 96820712.

It is a happy number.

It is a super-2 number, since 2×217028690² = 94202904566232200, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 217028690.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 471572 + ... + 472031.

It is an arithmetic number, because the mean of its divisors is an integer number (25477308).

Almost surely, 2^217028690 is an apocalyptic number.

217028690 is a deficient number, since it is larger than the sum of its proper divisors (190608238).

217028690 is a wasteful number, since it uses less digits than its factorization.

217028690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 943633.

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 217028690 is about 14731.8936325240. The cubic root of 217028690 is about 600.9509826644.

The spelling of 217028690 in words is "two hundred seventeen million, twenty-eight thousand, six hundred ninety".