217307923 has 16 divisors (see below), whose sum is σ = 271448064. Its totient is φ = 169649280.

The previous prime is 217307911. The next prime is 217307971. The reversal of 217307923 is 329703712.

It is a cyclic number.

It is not a de Polignac number, because 217307923 - 2¹⁷ = 217176851 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (217307983) 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, 25765 + ... + 33142.

It is an arithmetic number, because the mean of its divisors is an integer number (16965504).

Almost surely, 2^217307923 is an apocalyptic number.

217307923 is a deficient number, since it is larger than the sum of its proper divisors (54140141).

217307923 is a wasteful number, since it uses less digits than its factorization.

217307923 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58962.

The product of its (nonzero) digits is 15876, while the sum is 34.

The square root of 217307923 is about 14741.3677452264. The cubic root of 217307923 is about 601.2086036422.

The spelling of 217307923 in words is "two hundred seventeen million, three hundred seven thousand, nine hundred twenty-three".