217497947 has 2 divisors, whose sum is σ = 217497948. Its totient is φ = 217497946.

The previous prime is 217497923. The next prime is 217497971. The reversal of 217497947 is 749794712.

It is a balanced prime because it is at equal distance from previous prime (217497923) and next prime (217497971).

It is a cyclic number.

It is not a de Polignac number, because 217497947 - 2⁸ = 217497691 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 217497895 and 217497904.

It is not a weakly prime, because it can be changed into another prime (217497347) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108748973 + 108748974.

It is an arithmetic number, because the mean of its divisors is an integer number (108748974).

Almost surely, 2^217497947 is an apocalyptic number.

217497947 is a deficient number, since it is larger than the sum of its proper divisors (1).

217497947 is an equidigital number, since it uses as much as digits as its factorization.

217497947 is an evil number, because the sum of its binary digits is even.

The product of its digits is 889056, while the sum is 50.

The square root of 217497947 is about 14747.8116003697. The cubic root of 217497947 is about 601.3837940329.

The spelling of 217497947 in words is "two hundred seventeen million, four hundred ninety-seven thousand, nine hundred forty-seven".