136691257 has 2 divisors, whose sum is σ = 136691258. Its totient is φ = 136691256.

The previous prime is 136691227. The next prime is 136691287. The reversal of 136691257 is 752196631.

136691257 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a balanced prime because it is at equal distance from previous prime (136691227) and next prime (136691287).

It can be written as a sum of positive squares in only one way, i.e., 135978921 + 712336 = 11661^2 + 844^2 .

It is an emirp because it is prime and its reverse (752196631) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 136691257 - 2⁷ = 136691129 is a prime.

It is not a weakly prime, because it can be changed into another prime (136691207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 68345628 + 68345629.

It is an arithmetic number, because the mean of its divisors is an integer number (68345629).

Almost surely, 2^136691257 is an apocalyptic number.

It is an amenable number.

136691257 is a deficient number, since it is larger than the sum of its proper divisors (1).

136691257 is an equidigital number, since it uses as much as digits as its factorization.

136691257 is an evil number, because the sum of its binary digits is even.

The product of its digits is 68040, while the sum is 40.

The square root of 136691257 is about 11691.5036244274. The cubic root of 136691257 is about 515.1261286574.

The spelling of 136691257 in words is "one hundred thirty-six million, six hundred ninety-one thousand, two hundred fifty-seven".