240686681 has 2 divisors, whose sum is σ = 240686682. Its totient is φ = 240686680.

The previous prime is 240686659. The next prime is 240686683. The reversal of 240686681 is 186686042.

240686681 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 235776025 + 4910656 = 15355^2 + 2216^2 .

It is a cyclic number.

It is not a de Polignac number, because 240686681 - 2⁶ = 240686617 is a prime.

It is a super-2 number, since 2×240686681² = 115860156821591522, which contains 22 as substring.

Together with 240686683, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (240686683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 120343340 + 120343341.

It is an arithmetic number, because the mean of its divisors is an integer number (120343341).

Almost surely, 2^240686681 is an apocalyptic number.

It is an amenable number.

240686681 is a deficient number, since it is larger than the sum of its proper divisors (1).

240686681 is an equidigital number, since it uses as much as digits as its factorization.

240686681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 110592, while the sum is 41.

The square root of 240686681 is about 15514.0800887452. The cubic root of 240686681 is about 622.0386250281.

The spelling of 240686681 in words is "two hundred forty million, six hundred eighty-six thousand, six hundred eighty-one".