136868521 has 2 divisors, whose sum is σ = 136868522. Its totient is φ = 136868520.

The previous prime is 136868507. The next prime is 136868549. The reversal of 136868521 is 125868631.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 125552025 + 11316496 = 11205^2 + 3364^2 .

It is a cyclic number.

It is not a de Polignac number, because 136868521 - 2⁵ = 136868489 is a prime.

It is equal to p_7745188 and since 136868521 and 7745188 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (136862521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 68434260 + 68434261.

It is an arithmetic number, because the mean of its divisors is an integer number (68434261).

Almost surely, 2^136868521 is an apocalyptic number.

It is an amenable number.

136868521 is a deficient number, since it is larger than the sum of its proper divisors (1).

136868521 is an equidigital number, since it uses as much as digits as its factorization.

136868521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 69120, while the sum is 40.

The square root of 136868521 is about 11699.0820580078. The cubic root of 136868521 is about 515.3487078141.

The spelling of 136868521 in words is "one hundred thirty-six million, eight hundred sixty-eight thousand, five hundred twenty-one".