135721577 has 2 divisors, whose sum is σ = 135721578. Its totient is φ = 135721576.

The previous prime is 135721549. The next prime is 135721601. The reversal of 135721577 is 775127531.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 81198121 + 54523456 = 9011^2 + 7384^2 .

It is a cyclic number.

It is not a de Polignac number, because 135721577 - 2¹² = 135717481 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 135721577.

It is not a weakly prime, because it can be changed into another prime (135721177) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67860788 + 67860789.

It is an arithmetic number, because the mean of its divisors is an integer number (67860789).

Almost surely, 2^135721577 is an apocalyptic number.

It is an amenable number.

135721577 is a deficient number, since it is larger than the sum of its proper divisors (1).

135721577 is an equidigital number, since it uses as much as digits as its factorization.

135721577 is an odious number, because the sum of its binary digits is odd.

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

The square root of 135721577 is about 11649.9603861987. The cubic root of 135721577 is about 513.9051450776.

The spelling of 135721577 in words is "one hundred thirty-five million, seven hundred twenty-one thousand, five hundred seventy-seven".