136240781 has 2 divisors, whose sum is σ = 136240782. Its totient is φ = 136240780.

The previous prime is 136240759. The next prime is 136240817. The reversal of 136240781 is 187042631.

Together with next prime (136240817) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 74476900 + 61763881 = 8630^2 + 7859^2 .

It is a cyclic number.

It is not a de Polignac number, because 136240781 - 2⁶ = 136240717 is a prime.

It is a super-2 number, since 2×136240781² = 37123100814979922, which contains 22 as substring.

It is a congruent number.

It is a weakly prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 68120390 + 68120391.

It is an arithmetic number, because the mean of its divisors is an integer number (68120391).

Almost surely, 2^136240781 is an apocalyptic number.

It is an amenable number.

136240781 is a deficient number, since it is larger than the sum of its proper divisors (1).

136240781 is an equidigital number, since it uses as much as digits as its factorization.

136240781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 136240781 is about 11672.2226246761. Note that the first 3 decimals coincide. The cubic root of 136240781 is about 514.5596273183.

The spelling of 136240781 in words is "one hundred thirty-six million, two hundred forty thousand, seven hundred eighty-one".