135661013 has 4 divisors (see below), whose sum is σ = 135686220. Its totient is φ = 135635808.

The previous prime is 135660989. The next prime is 135661021. The reversal of 135661013 is 310166531.

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 108014449 + 27646564 = 10393^2 + 5258^2 .

It is a cyclic number.

It is not a de Polignac number, because 135661013 - 2⁸ = 135660757 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (135661033) by changing a digit.

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, 920 + ... + 16497.

It is an arithmetic number, because the mean of its divisors is an integer number (33921555).

Almost surely, 2^135661013 is an apocalyptic number.

It is an amenable number.

135661013 is a deficient number, since it is larger than the sum of its proper divisors (25207).

135661013 is an equidigital number, since it uses as much as digits as its factorization.

135661013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25206.

The product of its (nonzero) digits is 1620, while the sum is 26.

The square root of 135661013 is about 11647.3607740123. The cubic root of 135661013 is about 513.8286925277.

The spelling of 135661013 in words is "one hundred thirty-five million, six hundred sixty-one thousand, thirteen".