139744609 has 4 divisors (see below), whose sum is σ = 139942420. Its totient is φ = 139546800.

The previous prime is 139744603. The next prime is 139744637. The reversal of 139744609 is 906447931.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 906447931 = 4219 ⋅214849.

It can be written as a sum of positive squares in 2 ways, for example, as 56205009 + 83539600 = 7497^2 + 9140^2 .

It is a cyclic number.

It is not a de Polignac number, because 139744609 - 2¹³ = 139736417 is a prime.

It is not an unprimeable number, because it can be changed into a prime (139744603) 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, 97842 + ... + 99259.

It is an arithmetic number, because the mean of its divisors is an integer number (34985605).

Almost surely, 2^139744609 is an apocalyptic number.

It is an amenable number.

139744609 is a deficient number, since it is larger than the sum of its proper divisors (197811).

139744609 is an equidigital number, since it uses as much as digits as its factorization.

139744609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 197810.

The product of its (nonzero) digits is 163296, while the sum is 43.

The square root of 139744609 is about 11821.3624003327. The cubic root of 139744609 is about 518.9334760289.

The spelling of 139744609 in words is "one hundred thirty-nine million, seven hundred forty-four thousand, six hundred nine".