138695805 has 12 divisors (see below), whose sum is σ = 240406140. Its totient is φ = 73971072.

The previous prime is 138695789. The next prime is 138695807. The reversal of 138695805 is 508596831.

138695805 is a `hidden beast` number, since 1 + 3 + 8 + 69 + 580 + 5 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 44275716 + 94420089 = 6654^2 + 9717^2 .

It is not a de Polignac number, because 138695805 - 2⁴ = 138695789 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45), and also a Moran number because the ratio is a prime number: 3082129 = 138695805 / (1 + 3 + 8 + 6 + 9 + 5 + 8 + 0 + 5).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138695807) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1541020 + ... + 1541109.

It is an arithmetic number, because the mean of its divisors is an integer number (20033845).

Almost surely, 2^138695805 is an apocalyptic number.

138695805 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

138695805 is a deficient number, since it is larger than the sum of its proper divisors (101710335).

138695805 is a wasteful number, since it uses less digits than its factorization.

138695805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3082140 (or 3082137 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 45.

The square root of 138695805 is about 11776.9183150772. The cubic root of 138695805 is about 517.6319904170.

The spelling of 138695805 in words is "one hundred thirty-eight million, six hundred ninety-five thousand, eight hundred five".