217066390 has 8 divisors (see below), whose sum is σ = 390719520. Its totient is φ = 86826552.

The previous prime is 217066379. The next prime is 217066391. The reversal of 217066390 is 93660712.

217066390 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217066391) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10853310 + ... + 10853329.

It is an arithmetic number, because the mean of its divisors is an integer number (48839940).

Almost surely, 2^217066390 is an apocalyptic number.

217066390 is a deficient number, since it is larger than the sum of its proper divisors (173653130).

217066390 is a wasteful number, since it uses less digits than its factorization.

217066390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21706646.

The product of its (nonzero) digits is 13608, while the sum is 34.

The square root of 217066390 is about 14733.1731137593. The cubic root of 217066390 is about 600.9857776652.

The spelling of 217066390 in words is "two hundred seventeen million, sixty-six thousand, three hundred ninety".