139868509 has 8 divisors (see below), whose sum is σ = 154733760. Its totient is φ = 125361600.

The previous prime is 139868501. The next prime is 139868539. The reversal of 139868509 is 905868931.

139868509 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 139868509 - 2³ = 139868501 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (139868501) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 88764 + ... + 90325.

It is an arithmetic number, because the mean of its divisors is an integer number (19341720).

Almost surely, 2^139868509 is an apocalyptic number.

It is an amenable number.

139868509 is a deficient number, since it is larger than the sum of its proper divisors (14865251).

139868509 is a wasteful number, since it uses less digits than its factorization.

139868509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179171.

The product of its (nonzero) digits is 466560, while the sum is 49.

The square root of 139868509 is about 11826.6017519827. The cubic root of 139868509 is about 519.0867958733.

The spelling of 139868509 in words is "one hundred thirty-nine million, eight hundred sixty-eight thousand, five hundred nine".