136081681 has 2 divisors, whose sum is σ = 136081682. Its totient is φ = 136081680.

The previous prime is 136081679. The next prime is 136081697. The reversal of 136081681 is 186180631.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 134096400 + 1985281 = 11580^2 + 1409^2 .

It is a cyclic number.

It is not a de Polignac number, because 136081681 - 2¹ = 136081679 is a prime.

It is a super-2 number, since 2×136081681² = 37036447807571522, which contains 22 as substring.

Together with 136081679, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (136081181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 68040840 + 68040841.

It is an arithmetic number, because the mean of its divisors is an integer number (68040841).

Almost surely, 2^136081681 is an apocalyptic number.

It is an amenable number.

136081681 is a deficient number, since it is larger than the sum of its proper divisors (1).

136081681 is an equidigital number, since it uses as much as digits as its factorization.

136081681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6912, while the sum is 34.

The square root of 136081681 is about 11665.4053080037. The cubic root of 136081681 is about 514.3592508860.

The spelling of 136081681 in words is "one hundred thirty-six million, eighty-one thousand, six hundred eighty-one".