217121570671387 has 2 divisors, whose sum is σ = 217121570671388. Its totient is φ = 217121570671386.

The previous prime is 217121570671363. The next prime is 217121570671417. The reversal of 217121570671387 is 783176075121712.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-217121570671387 is a prime.

It is not a weakly prime, because it can be changed into another prime (217121570671787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108560785335693 + 108560785335694.

It is an arithmetic number, because the mean of its divisors is an integer number (108560785335694).

Almost surely, 2^{217121570671387} is an apocalyptic number.

217121570671387 is a deficient number, since it is larger than the sum of its proper divisors (1).

217121570671387 is an equidigital number, since it uses as much as digits as its factorization.

217121570671387 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6914880, while the sum is 58.

The spelling of 217121570671387 in words is "two hundred seventeen trillion, one hundred twenty-one billion, five hundred seventy million, six hundred seventy-one thousand, three hundred eighty-seven".