218244191497 has 2 divisors, whose sum is σ = 218244191498. Its totient is φ = 218244191496.

The previous prime is 218244191423. The next prime is 218244191569. The reversal of 218244191497 is 794191442812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 196435990521 + 21808200976 = 443211^2 + 147676^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-218244191497 is a prime.

It is not a weakly prime, because it can be changed into another prime (218244191597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109122095748 + 109122095749.

It is an arithmetic number, because the mean of its divisors is an integer number (109122095749).

Almost surely, 2^218244191497 is an apocalyptic number.

It is an amenable number.

218244191497 is a deficient number, since it is larger than the sum of its proper divisors (1).

218244191497 is an equidigital number, since it uses as much as digits as its factorization.

218244191497 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1161216, while the sum is 52.

The spelling of 218244191497 in words is "two hundred eighteen billion, two hundred forty-four million, one hundred ninety-one thousand, four hundred ninety-seven".