140209 has 4 divisors (see below), whose sum is σ = 141300. Its totient is φ = 139120.

The previous prime is 140207. The next prime is 140221. The reversal of 140209 is 902041.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 48400 + 91809 = 220^2 + 303^2 .

It is a cyclic number.

It is not a de Polignac number, because 140209 - 2¹ = 140207 is a prime.

It is a Duffinian number.

140209 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 140192 and 140201.

It is not an unprimeable number, because it can be changed into a prime (140207) 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, 322 + ... + 619.

It is an arithmetic number, because the mean of its divisors is an integer number (35325).

2¹⁴⁰²⁰⁹ is an apocalyptic number.

It is an amenable number.

140209 is a deficient number, since it is larger than the sum of its proper divisors (1091).

140209 is an equidigital number, since it uses as much as digits as its factorization.

140209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1090.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 140209 is about 374.4449225187. Note that the first 3 decimals coincide. The cubic root of 140209 is about 51.9507670110.

The spelling of 140209 in words is "one hundred forty thousand, two hundred nine".