140686809 has 4 divisors (see below), whose sum is σ = 187582416. Its totient is φ = 93791204.

The previous prime is 140686789. The next prime is 140686813. The reversal of 140686809 is 908686041.

140686809 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 908686041 = 3 ⋅302895347.

It is a cyclic number.

It is not a de Polignac number, because 140686809 - 2⁷ = 140686681 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (140686829) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23447799 + ... + 23447804.

It is an arithmetic number, because the mean of its divisors is an integer number (46895604).

Almost surely, 2^140686809 is an apocalyptic number.

It is an amenable number.

140686809 is a deficient number, since it is larger than the sum of its proper divisors (46895607).

140686809 is an equidigital number, since it uses as much as digits as its factorization.

140686809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46895606.

The product of its (nonzero) digits is 82944, while the sum is 42.

The square root of 140686809 is about 11861.1470355948. The cubic root of 140686809 is about 520.0971329891.

The spelling of 140686809 in words is "one hundred forty million, six hundred eighty-six thousand, eight hundred nine".