210868681 has 2 divisors, whose sum is σ = 210868682. Its totient is φ = 210868680.

The previous prime is 210868639. The next prime is 210868747. The reversal of 210868681 is 186868012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 154753600 + 56115081 = 12440^2 + 7491^2 .

It is a cyclic number.

It is not a de Polignac number, because 210868681 - 2¹⁷ = 210737609 is a prime.

It is a super-2 number, since 2×210868681² = 88931201253359522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (210868621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105434340 + 105434341.

It is an arithmetic number, because the mean of its divisors is an integer number (105434341).

Almost surely, 2^210868681 is an apocalyptic number.

It is an amenable number.

210868681 is a deficient number, since it is larger than the sum of its proper divisors (1).

210868681 is an equidigital number, since it uses as much as digits as its factorization.

210868681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36864, while the sum is 40.

The square root of 210868681 is about 14521.3181564209. The cubic root of 210868681 is about 595.2106506448.

The spelling of 210868681 in words is "two hundred ten million, eight hundred sixty-eight thousand, six hundred eighty-one".