135661331 has 4 divisors (see below), whose sum is σ = 146096832. Its totient is φ = 125225832.

The previous prime is 135661313. The next prime is 135661367. The reversal of 135661331 is 133166531.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 133166531 = 211 ⋅631121.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-135661331 is a prime.

It is a super-2 number, since 2×135661331² = 36807993457383122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 135661294 and 135661303.

It is not an unprimeable number, because it can be changed into a prime (135661231) 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, 5217731 + ... + 5217756.

It is an arithmetic number, because the mean of its divisors is an integer number (36524208).

Almost surely, 2^135661331 is an apocalyptic number.

135661331 is a deficient number, since it is larger than the sum of its proper divisors (10435501).

135661331 is a wasteful number, since it uses less digits than its factorization.

135661331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10435500.

The product of its digits is 4860, while the sum is 29.

The square root of 135661331 is about 11647.3744251655. The cubic root of 135661331 is about 513.8290940122.

The spelling of 135661331 in words is "one hundred thirty-five million, six hundred sixty-one thousand, three hundred thirty-one".