217320 has 32 divisors (see below), whose sum is σ = 652320. Its totient is φ = 57920.

The previous prime is 217319. The next prime is 217333. The reversal of 217320 is 23712.

217320 = T₃₀ + T₃₁ + ... + T₁₀₉.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a plaindrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 217320.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 217320.

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, 786 + ... + 1025.

It is an arithmetic number, because the mean of its divisors is an integer number (20385).

2²¹⁷³²⁰ is an apocalyptic number.

217320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

217320 is an abundant number, since it is smaller than the sum of its proper divisors (435000).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

217320 is a wasteful number, since it uses less digits than its factorization.

217320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1825 (or 1821 counting only the distinct ones).

The product of its (nonzero) digits is 84, while the sum is 15.

The square root of 217320 is about 466.1759324547. The cubic root of 217320 is about 60.1219740929.

The spelling of 217320 in words is "two hundred seventeen thousand, three hundred twenty", and thus it is an iban number.