136331981 has 2 divisors, whose sum is σ = 136331982. Its totient is φ = 136331980.

The previous prime is 136331957. The next prime is 136332029. The reversal of 136331981 is 189133631.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 122456356 + 13875625 = 11066^2 + 3725^2 .

It is a cyclic number.

It is not a de Polignac number, because 136331981 - 2⁶ = 136331917 is a prime.

It is a super-2 number, since 2×136331981² = 37172818086768722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (136331941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 68165990 + 68165991.

It is an arithmetic number, because the mean of its divisors is an integer number (68165991).

Almost surely, 2^136331981 is an apocalyptic number.

It is an amenable number.

136331981 is a deficient number, since it is larger than the sum of its proper divisors (1).

136331981 is an equidigital number, since it uses as much as digits as its factorization.

136331981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11664, while the sum is 35.

The square root of 136331981 is about 11676.1286820590. The cubic root of 136331981 is about 514.6744176436.

The spelling of 136331981 in words is "one hundred thirty-six million, three hundred thirty-one thousand, nine hundred eighty-one".