139013209 has 4 divisors (see below), whose sum is σ = 139197604. Its totient is φ = 138828816.

The previous prime is 139013111. The next prime is 139013213. The reversal of 139013209 is 902310931.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 52243984 + 86769225 = 7228^2 + 9315^2 .

It is a cyclic number.

It is not a de Polignac number, because 139013209 - 2¹⁷ = 138882137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (139013299) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 91062 + ... + 92575.

It is an arithmetic number, because the mean of its divisors is an integer number (34799401).

Almost surely, 2^139013209 is an apocalyptic number.

It is an amenable number.

139013209 is a deficient number, since it is larger than the sum of its proper divisors (184395).

139013209 is an equidigital number, since it uses as much as digits as its factorization.

139013209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 184394.

The product of its (nonzero) digits is 1458, while the sum is 28.

The square root of 139013209 is about 11790.3862956224. The cubic root of 139013209 is about 518.0265548419.

The spelling of 139013209 in words is "one hundred thirty-nine million, thirteen thousand, two hundred nine".