135861009 has 4 divisors (see below), whose sum is σ = 181148016. Its totient is φ = 90574004.

The previous prime is 135860981. The next prime is 135861071. The reversal of 135861009 is 900168531.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 135861009 - 2¹³ = 135852817 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (135861079) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22643499 + ... + 22643504.

It is an arithmetic number, because the mean of its divisors is an integer number (45287004).

Almost surely, 2^135861009 is an apocalyptic number.

It is an amenable number.

135861009 is a deficient number, since it is larger than the sum of its proper divisors (45287007).

135861009 is an equidigital number, since it uses as much as digits as its factorization.

135861009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45287006.

The product of its (nonzero) digits is 6480, while the sum is 33.

The square root of 135861009 is about 11655.9430763881. The cubic root of 135861009 is about 514.0810696919.

The spelling of 135861009 in words is "one hundred thirty-five million, eight hundred sixty-one thousand, nine".