139905 has 12 divisors (see below), whose sum is σ = 242580. Its totient is φ = 74592.

The previous prime is 139901. The next prime is 139907. The reversal of 139905 is 509931.

It can be written as a sum of positive squares in 2 ways, for example, as 36864 + 103041 = 192^2 + 321^2 .

It is not a de Polignac number, because 139905 - 2² = 139901 is a prime.

139905 is a lucky number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 139905.

It is not an unprimeable number, because it can be changed into a prime (139901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1510 + ... + 1599.

It is an arithmetic number, because the mean of its divisors is an integer number (20215).

139905 is a Friedman number, since it can be written as 3109*9*5, using all its digits and the basic arithmetic operations.

2¹³⁹⁹⁰⁵ is an apocalyptic number.

139905 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

139905 is a deficient number, since it is larger than the sum of its proper divisors (102675).

139905 is a wasteful number, since it uses less digits than its factorization.

139905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3120 (or 3117 counting only the distinct ones).

The product of its (nonzero) digits is 1215, while the sum is 27.

The square root of 139905 is about 374.0387680442. The cubic root of 139905 is about 51.9131934338.

The spelling of 139905 in words is "one hundred thirty-nine thousand, nine hundred five".