139938109 has 4 divisors (see below), whose sum is σ = 139977180. Its totient is φ = 139899040.

The previous prime is 139938091. The next prime is 139938157. The reversal of 139938109 is 901839931.

139938109 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 901839931 = 607 ⋅1485733.

It can be written as a sum of positive squares in 2 ways, for example, as 95981209 + 43956900 = 9797^2 + 6630^2 .

It is a cyclic number.

It is not a de Polignac number, because 139938109 - 2⁷ = 139937981 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 (139938199) 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, 13552 + ... + 21529.

It is an arithmetic number, because the mean of its divisors is an integer number (34994295).

Almost surely, 2^139938109 is an apocalyptic number.

It is an amenable number.

139938109 is a deficient number, since it is larger than the sum of its proper divisors (39071).

139938109 is an equidigital number, since it uses as much as digits as its factorization.

139938109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39070.

The product of its (nonzero) digits is 52488, while the sum is 43.

The square root of 139938109 is about 11829.5439049864. The cubic root of 139938109 is about 519.1728825611.

The spelling of 139938109 in words is "one hundred thirty-nine million, nine hundred thirty-eight thousand, one hundred nine".