135994981 has 2 divisors, whose sum is σ = 135994982. Its totient is φ = 135994980.

The previous prime is 135994931. The next prime is 135994987. The reversal of 135994981 is 189499531.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 111492481 + 24502500 = 10559^2 + 4950^2 .

It is a cyclic number.

It is not a de Polignac number, because 135994981 - 2¹⁹ = 135470693 is a prime.

It is a super-2 number, since 2×135994981² = 36989269714380722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (135994987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67997490 + 67997491.

It is an arithmetic number, because the mean of its divisors is an integer number (67997491).

Almost surely, 2^135994981 is an apocalyptic number.

It is an amenable number.

135994981 is a deficient number, since it is larger than the sum of its proper divisors (1).

135994981 is an equidigital number, since it uses as much as digits as its factorization.

135994981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 349920, while the sum is 49.

The square root of 135994981 is about 11661.6885998555. The cubic root of 135994981 is about 514.2499919449.

The spelling of 135994981 in words is "one hundred thirty-five million, nine hundred ninety-four thousand, nine hundred eighty-one".