138999565 has 32 divisors (see below), whose sum is σ = 183120480. Its totient is φ = 100859904.

The previous prime is 138999559. The next prime is 138999571. The reversal of 138999565 is 565999831.

It is an interprime number because it is at equal distance from previous prime (138999559) and next prime (138999571).

It can be written as a sum of positive squares in 16 ways, for example, as 184041 + 138815524 = 429^2 + 11782^2 .

It is a cyclic number.

It is not a de Polignac number, because 138999565 - 2⁷ = 138999437 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 31 ways as a sum of consecutive naturals, for example, 606871 + ... + 607099.

It is an arithmetic number, because the mean of its divisors is an integer number (5722515).

Almost surely, 2^138999565 is an apocalyptic number.

It is an amenable number.

138999565 is a deficient number, since it is larger than the sum of its proper divisors (44120915).

138999565 is a wasteful number, since it uses less digits than its factorization.

138999565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 481.

The product of its digits is 2624400, while the sum is 55.

The square root of 138999565 is about 11789.8076744279. The cubic root of 138999565 is about 518.0096063672.

The spelling of 138999565 in words is "one hundred thirty-eight million, nine hundred ninety-nine thousand, five hundred sixty-five".