138905965 has 16 divisors (see below), whose sum is σ = 182238336. Its totient is φ = 100801600.

The previous prime is 138905927. The next prime is 138905971. The reversal of 138905965 is 569509831.

It is not a de Polignac number, because 138905965 - 2¹¹ = 138903917 is a prime.

It is a super-2 number, since 2×138905965² = 38589734225162450, which contains 22 as substring.

It is a Duffinian number.

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, 25155 + ... + 30175.

It is an arithmetic number, because the mean of its divisors is an integer number (11389896).

Almost surely, 2^138905965 is an apocalyptic number.

It is an amenable number.

138905965 is a deficient number, since it is larger than the sum of its proper divisors (43332371).

138905965 is a wasteful number, since it uses less digits than its factorization.

138905965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5540.

The product of its (nonzero) digits is 291600, while the sum is 46.

The square root of 138905965 is about 11785.8374755467. The cubic root of 138905965 is about 517.8933072349.

The spelling of 138905965 in words is "one hundred thirty-eight million, nine hundred five thousand, nine hundred sixty-five".