139165409 has 4 divisors (see below), whose sum is σ = 139214640. Its totient is φ = 139116180.

The previous prime is 139165393. The next prime is 139165421. The reversal of 139165409 is 904561931.

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.

It is a cyclic number.

It is not a de Polignac number, because 139165409 - 2⁴ = 139165393 is a prime.

It is a super-2 number, since 2×139165409² = 38734022124274562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (139165469) 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, 20099 + ... + 26120.

It is an arithmetic number, because the mean of its divisors is an integer number (34803660).

Almost surely, 2^139165409 is an apocalyptic number.

It is an amenable number.

139165409 is a deficient number, since it is larger than the sum of its proper divisors (49231).

139165409 is an equidigital number, since it uses as much as digits as its factorization.

139165409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49230.

The product of its (nonzero) digits is 29160, while the sum is 38.

The square root of 139165409 is about 11796.8389410045. The cubic root of 139165409 is about 518.2155414028.

The spelling of 139165409 in words is "one hundred thirty-nine million, one hundred sixty-five thousand, four hundred nine".