136811905 has 4 divisors (see below), whose sum is σ = 164174292. Its totient is φ = 109449520.

The previous prime is 136811891. The next prime is 136811929. The reversal of 136811905 is 509118631.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 77228944 + 59582961 = 8788^2 + 7719^2 .

It is a de Polignac number, because none of the positive numbers 2^k-136811905 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 13681186 + ... + 13681195.

It is an arithmetic number, because the mean of its divisors is an integer number (41043573).

Almost surely, 2^136811905 is an apocalyptic number.

It is an amenable number.

136811905 is a deficient number, since it is larger than the sum of its proper divisors (27362387).

136811905 is an equidigital number, since it uses as much as digits as its factorization.

136811905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27362386.

The product of its (nonzero) digits is 6480, while the sum is 34.

The square root of 136811905 is about 11696.6621307106. The cubic root of 136811905 is about 515.2776395943.

The spelling of 136811905 in words is "one hundred thirty-six million, eight hundred eleven thousand, nine hundred five".