2197785665237 has 2 divisors, whose sum is σ = 2197785665238. Its totient is φ = 2197785665236.

The previous prime is 2197785665219. The next prime is 2197785665239. The reversal of 2197785665237 is 7325665877912.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1607725097521 + 590060567716 = 1267961^2 + 768154^2 .

It is a cyclic number.

It is not a de Polignac number, because 2197785665237 - 2¹⁰ = 2197785664213 is a prime.

Together with 2197785665239, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2197785665239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1098892832618 + 1098892832619.

It is an arithmetic number, because the mean of its divisors is an integer number (1098892832619).

Almost surely, 2^{2197785665237} is an apocalyptic number.

It is an amenable number.

2197785665237 is a deficient number, since it is larger than the sum of its proper divisors (1).

2197785665237 is an equidigital number, since it uses as much as digits as its factorization.

2197785665237 is an evil number, because the sum of its binary digits is even.

The product of its digits is 266716800, while the sum is 68.

The spelling of 2197785665237 in words is "two trillion, one hundred ninety-seven billion, seven hundred eighty-five million, six hundred sixty-five thousand, two hundred thirty-seven".