217490306641 has 2 divisors, whose sum is σ = 217490306642. Its totient is φ = 217490306640.

The previous prime is 217490306603. The next prime is 217490306681. The reversal of 217490306641 is 146603094712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 211834665025 + 5655641616 = 460255^2 + 75204^2 .

It is a cyclic number.

It is not a de Polignac number, because 217490306641 - 2¹⁵ = 217490273873 is a prime.

It is not a weakly prime, because it can be changed into another prime (217490306681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108745153320 + 108745153321.

It is an arithmetic number, because the mean of its divisors is an integer number (108745153321).

Almost surely, 2^217490306641 is an apocalyptic number.

It is an amenable number.

217490306641 is a deficient number, since it is larger than the sum of its proper divisors (1).

217490306641 is an equidigital number, since it uses as much as digits as its factorization.

217490306641 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 217728, while the sum is 43.

The spelling of 217490306641 in words is "two hundred seventeen billion, four hundred ninety million, three hundred six thousand, six hundred forty-one".