217632608891 has 2 divisors, whose sum is σ = 217632608892. Its totient is φ = 217632608890.

The previous prime is 217632608887. The next prime is 217632608969. The reversal of 217632608891 is 198806236712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 217632608891 - 2² = 217632608887 is a prime.

It is not a weakly prime, because it can be changed into another prime (217632608801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108816304445 + 108816304446.

It is an arithmetic number, because the mean of its divisors is an integer number (108816304446).

Almost surely, 2^217632608891 is an apocalyptic number.

217632608891 is a deficient number, since it is larger than the sum of its proper divisors (1).

217632608891 is an equidigital number, since it uses as much as digits as its factorization.

217632608891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1741824, while the sum is 53.

The spelling of 217632608891 in words is "two hundred seventeen billion, six hundred thirty-two million, six hundred eight thousand, eight hundred ninety-one".