138632805 has 12 divisors (see below), whose sum is σ = 240296940. Its totient is φ = 73937472.

The previous prime is 138632803. The next prime is 138632833. The reversal of 138632805 is 508236831.

138632805 is a `hidden beast` number, since 13 + 8 + 632 + 8 + 0 + 5 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 27815076 + 110817729 = 5274^2 + 10527^2 .

It is not a de Polignac number, because 138632805 - 2¹ = 138632803 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 138632805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138632801) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 1540320 + ... + 1540409.

It is an arithmetic number, because the mean of its divisors is an integer number (20024745).

Almost surely, 2^138632805 is an apocalyptic number.

138632805 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

138632805 is a deficient number, since it is larger than the sum of its proper divisors (101664135).

138632805 is a wasteful number, since it uses less digits than its factorization.

138632805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3080740 (or 3080737 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 138632805 is about 11774.2432877871. The cubic root of 138632805 is about 517.5536036332.

It can be divided in two parts, 1386 and 32805, that added together give a triangular number (34191 = T₂₆₁).

The spelling of 138632805 in words is "one hundred thirty-eight million, six hundred thirty-two thousand, eight hundred five".