217635312091013 has 2 divisors, whose sum is σ = 217635312091014. Its totient is φ = 217635312091012.

The previous prime is 217635312090979. The next prime is 217635312091033. The reversal of 217635312091013 is 310190213536712.

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., 215884924878529 + 1750387212484 = 14693023^2 + 1323022^2 .

It is a cyclic number.

It is not a de Polignac number, because 217635312091013 - 2⁶ = 217635312090949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (217635312091033) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108817656045506 + 108817656045507.

It is an arithmetic number, because the mean of its divisors is an integer number (108817656045507).

Almost surely, 2^{217635312091013} is an apocalyptic number.

It is an amenable number.

217635312091013 is a deficient number, since it is larger than the sum of its proper divisors (1).

217635312091013 is an equidigital number, since it uses as much as digits as its factorization.

217635312091013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 204120, while the sum is 44.

The spelling of 217635312091013 in words is "two hundred seventeen trillion, six hundred thirty-five billion, three hundred twelve million, ninety-one thousand, thirteen".