135611507861 has 4 divisors (see below), whose sum is σ = 135647170752. Its totient is φ = 135575844972.

The previous prime is 135611507849. The next prime is 135611507869. The reversal of 135611507861 is 168705116531.

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, and also an emirpimes, since its reverse is a distinct semiprime: 168705116531 = 7 ⋅24100730933.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-135611507861 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 (135611507869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17825741 + ... + 17833346.

It is an arithmetic number, because the mean of its divisors is an integer number (33911792688).

Almost surely, 2^135611507861 is an apocalyptic number.

It is an amenable number.

135611507861 is a deficient number, since it is larger than the sum of its proper divisors (35662891).

135611507861 is an equidigital number, since it uses as much as digits as its factorization.

135611507861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35662890.

The product of its (nonzero) digits is 151200, while the sum is 44.

The spelling of 135611507861 in words is "one hundred thirty-five billion, six hundred eleven million, five hundred seven thousand, eight hundred sixty-one".