135985961 has 2 divisors, whose sum is σ = 135985962. Its totient is φ = 135985960.

The previous prime is 135985951. The next prime is 135985963. The reversal of 135985961 is 169589531.

135985961 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 135582736 + 403225 = 11644^2 + 635^2 .

It is a cyclic number.

It is not a de Polignac number, because 135985961 - 2¹⁴ = 135969577 is a prime.

Together with 135985963, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (135985963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67992980 + 67992981.

It is an arithmetic number, because the mean of its divisors is an integer number (67992981).

Almost surely, 2^135985961 is an apocalyptic number.

It is an amenable number.

135985961 is a deficient number, since it is larger than the sum of its proper divisors (1).

135985961 is an equidigital number, since it uses as much as digits as its factorization.

135985961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 291600, while the sum is 47.

The square root of 135985961 is about 11661.3018569969. The cubic root of 135985961 is about 514.2386223157.

The spelling of 135985961 in words is "one hundred thirty-five million, nine hundred eighty-five thousand, nine hundred sixty-one".