978217 has 2 divisors, whose sum is σ = 978218. Its totient is φ = 978216.

The previous prime is 978209. The next prime is 978223. The reversal of 978217 is 712879.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 724201 + 254016 = 851^2 + 504^2 .

It is a cyclic number.

It is not a de Polignac number, because 978217 - 2³ = 978209 is a prime.

It is not a weakly prime, because it can be changed into another prime (978277) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 489108 + 489109.

It is an arithmetic number, because the mean of its divisors is an integer number (489109).

2⁹⁷⁸²¹⁷ is an apocalyptic number.

It is an amenable number.

978217 is a deficient number, since it is larger than the sum of its proper divisors (1).

978217 is an equidigital number, since it uses as much as digits as its factorization.

978217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7056, while the sum is 34.

The square root of 978217 is about 989.0485326818. The cubic root of 978217 is about 99.2685630437.

It can be divided in two parts, 978 and 217, that multiplied together give a triangular number (212226 = T₆₅₁).

The spelling of 978217 in words is "nine hundred seventy-eight thousand, two hundred seventeen".