138913865 has 16 divisors (see below), whose sum is σ = 171072000. Its totient is φ = 108229632.

The previous prime is 138913861. The next prime is 138913867. The reversal of 138913865 is 568319831.

It is a cyclic number.

It is not a de Polignac number, because 138913865 - 2² = 138913861 is a prime.

It is not an unprimeable number, because it can be changed into a prime (138913861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 95816 + ... + 97254.

It is an arithmetic number, because the mean of its divisors is an integer number (10692000).

Almost surely, 2^138913865 is an apocalyptic number.

It is an amenable number.

138913865 is a deficient number, since it is larger than the sum of its proper divisors (32158135).

138913865 is a wasteful number, since it uses less digits than its factorization.

138913865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1936.

The product of its digits is 155520, while the sum is 44.

The square root of 138913865 is about 11786.1726187936. The cubic root of 138913865 is about 517.9031250988.

The spelling of 138913865 in words is "one hundred thirty-eight million, nine hundred thirteen thousand, eight hundred sixty-five".