138841805 has 16 divisors (see below), whose sum is σ = 176690160. Its totient is φ = 104374272.

The previous prime is 138841799. The next prime is 138841817. The reversal of 138841805 is 508148831.

It can be written as a sum of positive squares in 8 ways, for example, as 4791721 + 134050084 = 2189^2 + 11578^2 .

It is a cyclic number.

It is not a de Polignac number, because 138841805 - 2⁶ = 138841741 is a prime.

It is a congruent 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 in 15 ways as a sum of consecutive naturals, for example, 92501 + ... + 93989.

It is an arithmetic number, because the mean of its divisors is an integer number (11043135).

Almost surely, 2^138841805 is an apocalyptic number.

It is an amenable number.

138841805 is a deficient number, since it is larger than the sum of its proper divisors (37848355).

138841805 is a wasteful number, since it uses less digits than its factorization.

138841805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2608.

The product of its (nonzero) digits is 30720, while the sum is 38.

The square root of 138841805 is about 11783.1152502214. The cubic root of 138841805 is about 517.8135574755.

The spelling of 138841805 in words is "one hundred thirty-eight million, eight hundred forty-one thousand, eight hundred five".