139389509 has 4 divisors (see below), whose sum is σ = 159302304. Its totient is φ = 119476716.

The previous prime is 139389487. The next prime is 139389541. The reversal of 139389509 is 905983931.

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: 905983931 = 6011 ⋅150721.

It is a cyclic number.

It is not a de Polignac number, because 139389509 - 2⁸ = 139389253 is a prime.

It is a super-2 number, since 2×139389509² = 38858870438522162, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (139389559) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9956387 + ... + 9956400.

It is an arithmetic number, because the mean of its divisors is an integer number (39825576).

Almost surely, 2^139389509 is an apocalyptic number.

It is an amenable number.

139389509 is a deficient number, since it is larger than the sum of its proper divisors (19912795).

139389509 is an equidigital number, since it uses as much as digits as its factorization.

139389509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19912794.

The product of its (nonzero) digits is 262440, while the sum is 47.

The square root of 139389509 is about 11806.3334274448. Note that the first 3 decimals coincide. The cubic root of 139389509 is about 518.4935554653.

The spelling of 139389509 in words is "one hundred thirty-nine million, three hundred eighty-nine thousand, five hundred nine".