135191961 has 24 divisors (see below), whose sum is σ = 202974720. Its totient is φ = 86616000.

The previous prime is 135191909. The next prime is 135191963. The reversal of 135191961 is 169191531.

It is a happy number.

135191961 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 135191961 - 2¹¹ = 135189913 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (135191963) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 40525 + ... + 43733.

It is an arithmetic number, because the mean of its divisors is an integer number (8457280).

Almost surely, 2^135191961 is an apocalyptic number.

It is an amenable number.

135191961 is a deficient number, since it is larger than the sum of its proper divisors (67782759).

135191961 is a wasteful number, since it uses less digits than its factorization.

135191961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3397 (or 3394 counting only the distinct ones).

The product of its digits is 7290, while the sum is 36.

The square root of 135191961 is about 11627.2077903510. The cubic root of 135191961 is about 513.2358160274.

The spelling of 135191961 in words is "one hundred thirty-five million, one hundred ninety-one thousand, nine hundred sixty-one".