217296491 has 2 divisors, whose sum is σ = 217296492. Its totient is φ = 217296490.

The previous prime is 217296467. The next prime is 217296493. The reversal of 217296491 is 194692712.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-217296491 is a prime.

Together with 217296493, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (217296493) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108648245 + 108648246.

It is an arithmetic number, because the mean of its divisors is an integer number (108648246).

Almost surely, 2^217296491 is an apocalyptic number.

217296491 is a deficient number, since it is larger than the sum of its proper divisors (1).

217296491 is an equidigital number, since it uses as much as digits as its factorization.

217296491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 54432, while the sum is 41.

The square root of 217296491 is about 14740.9799877756. The cubic root of 217296491 is about 601.1980607880.

The spelling of 217296491 in words is "two hundred seventeen million, two hundred ninety-six thousand, four hundred ninety-one".