139918 has 4 divisors (see below), whose sum is σ = 209880. Its totient is φ = 69958.

The previous prime is 139907. The next prime is 139921. The reversal of 139918 is 819931.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 819931 = 7 ⋅117133.

It is an Ulam number.

It is a plaindrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 139918.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34978 + ... + 34981.

It is an arithmetic number, because the mean of its divisors is an integer number (52470).

2¹³⁹⁹¹⁸ is an apocalyptic number.

139918 is a deficient number, since it is larger than the sum of its proper divisors (69962).

139918 is an equidigital number, since it uses as much as digits as its factorization.

139918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69961.

The product of its digits is 1944, while the sum is 31.

The square root of 139918 is about 374.0561455183. The cubic root of 139918 is about 51.9148013120.

The spelling of 139918 in words is "one hundred thirty-nine thousand, nine hundred eighteen".