135721757 has 2 divisors, whose sum is σ = 135721758. Its totient is φ = 135721756.

The previous prime is 135721739. The next prime is 135721823. The reversal of 135721757 is 757127531.

135721757 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 96609241 + 39112516 = 9829^2 + 6254^2 .

It is a cyclic number.

It is not a de Polignac number, because 135721757 - 2⁸ = 135721501 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 135721757.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (135721457) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67860878 + 67860879.

It is an arithmetic number, because the mean of its divisors is an integer number (67860879).

Almost surely, 2^135721757 is an apocalyptic number.

It is an amenable number.

135721757 is a deficient number, since it is larger than the sum of its proper divisors (1).

135721757 is an equidigital number, since it uses as much as digits as its factorization.

135721757 is an evil number, because the sum of its binary digits is even.

The product of its digits is 51450, while the sum is 38.

The square root of 135721757 is about 11649.9681115443. The cubic root of 135721757 is about 513.9053722655.

The spelling of 135721757 in words is "one hundred thirty-five million, seven hundred twenty-one thousand, seven hundred fifty-seven".