136666881 has 12 divisors (see below), whose sum is σ = 212593108. Its totient is φ = 84102624.

The previous prime is 136666819. The next prime is 136666903. The reversal of 136666881 is 188666631.

It can be written as a sum of positive squares in 2 ways, for example, as 48776256 + 87890625 = 6984^2 + 9375^2 .

It is not a de Polignac number, because 136666881 - 2¹⁴ = 136650497 is a prime.

It is a super-2 number, since 2×136666881² = 37355672724536322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (136666181) 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 in 11 ways as a sum of consecutive naturals, for example, 583930 + ... + 584163.

Almost surely, 2^136666881 is an apocalyptic number.

It is an amenable number.

136666881 is a deficient number, since it is larger than the sum of its proper divisors (75926227).

136666881 is a wasteful number, since it uses less digits than its factorization.

136666881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1168112 (or 1168109 counting only the distinct ones).

The product of its digits is 248832, while the sum is 45.

The square root of 136666881 is about 11690.4611115216. The cubic root of 136666881 is about 515.0955062136.

The spelling of 136666881 in words is "one hundred thirty-six million, six hundred sixty-six thousand, eight hundred eighty-one".