210539299661 has 2 divisors, whose sum is σ = 210539299662. Its totient is φ = 210539299660.

The previous prime is 210539299651. The next prime is 210539299697. The reversal of 210539299661 is 166992935012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 209941741636 + 597558025 = 458194^2 + 24445^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-210539299661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (210539299601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105269649830 + 105269649831.

It is an arithmetic number, because the mean of its divisors is an integer number (105269649831).

Almost surely, 2^210539299661 is an apocalyptic number.

It is an amenable number.

210539299661 is a deficient number, since it is larger than the sum of its proper divisors (1).

210539299661 is an equidigital number, since it uses as much as digits as its factorization.

210539299661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1574640, while the sum is 53.

The spelling of 210539299661 in words is "two hundred ten billion, five hundred thirty-nine million, two hundred ninety-nine thousand, six hundred sixty-one".