136810121986 has 4 divisors (see below), whose sum is σ = 205215182982. Its totient is φ = 68405060992.

The previous prime is 136810121983. The next prime is 136810121989. The reversal of 136810121986 is 689121018631.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 689121018631 = 127 ⋅5426149753.

It is an interprime number because it is at equal distance from previous prime (136810121983) and next prime (136810121989).

It can be written as a sum of positive squares in only one way, i.e., 111519263025 + 25290858961 = 333945^2 + 159031^2 .

It is not an unprimeable number, because it can be changed into a prime (136810121983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34202530495 + ... + 34202530498.

Almost surely, 2^136810121986 is an apocalyptic number.

136810121986 is a deficient number, since it is larger than the sum of its proper divisors (68405060996).

136810121986 is an equidigital number, since it uses as much as digits as its factorization.

136810121986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68405060995.

The product of its (nonzero) digits is 124416, while the sum is 46.

The spelling of 136810121986 in words is "one hundred thirty-six billion, eight hundred ten million, one hundred twenty-one thousand, nine hundred eighty-six".