139831418 has 4 divisors (see below), whose sum is σ = 209747130. Its totient is φ = 69915708.

The previous prime is 139831397. The next prime is 139831423. The reversal of 139831418 is 814138931.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 814138931 = 131 ⋅6214801.

It can be written as a sum of positive squares in only one way, i.e., 116143729 + 23687689 = 10777^2 + 4867^2 .

It is a Curzon number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 34957853 + ... + 34957856.

Almost surely, 2^139831418 is an apocalyptic number.

139831418 is a deficient number, since it is larger than the sum of its proper divisors (69915712).

139831418 is an equidigital number, since it uses as much as digits as its factorization.

139831418 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69915711.

The product of its digits is 20736, while the sum is 38.

The square root of 139831418 is about 11825.0335306079. The cubic root of 139831418 is about 519.0409071772.

The spelling of 139831418 in words is "one hundred thirty-nine million, eight hundred thirty-one thousand, four hundred eighteen".