217901 has 2 divisors, whose sum is σ = 217902. Its totient is φ = 217900.

The previous prime is 217859. The next prime is 217907. The reversal of 217901 is 109712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 121801 + 96100 = 349^2 + 310^2 .

It is a cyclic number.

It is not a de Polignac number, because 217901 - 2¹⁰ = 216877 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (217907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108950 + 108951.

It is an arithmetic number, because the mean of its divisors is an integer number (108951).

2²¹⁷⁹⁰¹ is an apocalyptic number.

It is an amenable number.

217901 is a deficient number, since it is larger than the sum of its proper divisors (1).

217901 is an equidigital number, since it uses as much as digits as its factorization.

217901 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 126, while the sum is 20.

The square root of 217901 is about 466.7986718062. The cubic root of 217901 is about 60.1755046533.

The spelling of 217901 in words is "two hundred seventeen thousand, nine hundred one".