217801013 has 2 divisors, whose sum is σ = 217801014. Its totient is φ = 217801012.

The previous prime is 217800959. The next prime is 217801027. The reversal of 217801013 is 310108712.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 163660849 + 54140164 = 12793^2 + 7358^2 .

It is a cyclic number.

It is not a de Polignac number, because 217801013 - 2⁸ = 217800757 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 217801013.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (217801813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108900506 + 108900507.

It is an arithmetic number, because the mean of its divisors is an integer number (108900507).

Almost surely, 2^217801013 is an apocalyptic number.

It is an amenable number.

217801013 is a deficient number, since it is larger than the sum of its proper divisors (1).

217801013 is an equidigital number, since it uses as much as digits as its factorization.

217801013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 336, while the sum is 23.

The square root of 217801013 is about 14758.0829717142. The cubic root of 217801013 is about 601.6629911387.

Adding to 217801013 its reverse (310108712), we get a palindrome (527909725).

The spelling of 217801013 in words is "two hundred seventeen million, eight hundred one thousand, thirteen".