210340259681 has 2 divisors, whose sum is σ = 210340259682. Its totient is φ = 210340259680.

The previous prime is 210340259653. The next prime is 210340259743. The reversal of 210340259681 is 186952043012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 168887299681 + 41452960000 = 410959^2 + 203600^2 .

It is a cyclic number.

It is not a de Polignac number, because 210340259681 - 2¹⁰ = 210340258657 is a prime.

It is a super-2 number, since 2×210340259681² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (210340259611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105170129840 + 105170129841.

It is an arithmetic number, because the mean of its divisors is an integer number (105170129841).

Almost surely, 2^210340259681 is an apocalyptic number.

It is an amenable number.

210340259681 is a deficient number, since it is larger than the sum of its proper divisors (1).

210340259681 is an equidigital number, since it uses as much as digits as its factorization.

210340259681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 103680, while the sum is 41.

The spelling of 210340259681 in words is "two hundred ten billion, three hundred forty million, two hundred fifty-nine thousand, six hundred eighty-one".